ТМ 9-270
TECHNICAL MANUAL
COMMON WOOD AND
METAL REPAIR
HEADQUARTERS, DEPARTMENT OF THE ARMY
MARCH 1971
*ТМ 9-270
Technical Manual
No. 9-270
HEADQUARTERS
DEPARTMENT OF THE ARMY
Washington, D.C., 18 March 1971
COMMON WOOD AND METAL REPAIR
Paragraph	Page
Chapter 1. INTRODUCTION
Purpose ________________________________________________________________________- 1-1	1-1
Scope ..  ______________________________________________________________________ 1-2	1-1
Recommended changes ____________________________________________________________ 1-3	1-1
2. REPAIR OF WOOD, PLYWOOD, AND FIBER ITEMS
Section I. Basic repair
General ________________________________________________________________________ 2-1	2-1
Gluing __ ______________________________________________________________________ 2-2	2—1
II.	Repair of components
Warped parts ___________________________________________________________________ 2-3	2-4
Broken parts ___________________________________________________________________ 2-4	2-4
Surface parts __ _______________________________________________________________ 2-5	2-6
Joints _________________________________________________________________________ 2-6	2-7
Fastenings and attachments______________________________________________________ 2-7	2-8
Upholstery _____________________________________________________________________ 2-8	2-11
III.	Reflnishing
Preparation of surface _________________________________________________________ 2-9	2-13
Materials ______________________________________________________________________ 2-10	2-15
Methods of application _________________________________________________________ 2-11	2-16
Inspection _____________________________________________________________________ 2-12	2-16
Chapter 3.	REPAIR OF TOOLS AND IMPLEMENTS
Section I. Basic repair
Responsibility __________________ ______________________________________________ 3-1	3-1
Cleaning _______________________________________________________________________ 3-2	3-1
Straightening _ ________________________________________________________________ 3-3	3-2
Shaping and sharpening _________________________________________________________ 3-4	3-2
Procedures for shaping and sharpening ___________________ ______________________ 3-5	3-4
Heat treating___________________________________________________________________ 3-6	3-6
Brazing ______ _________________________________________________________________ 3-7	3-8
Welding __________________,_____________________________________________________ 3-8	3-8
Oiling _________________________________________________________________________ 3-9	3-8
II.	Repair of components
Handles ________________________________________________________________________ 3-10	3-8
Tcol handle heads	. .. ____________________________ ___________________________ 3-11	3-11
III.	Refinishing
Preparation of surface _________________________________________________________ 3-12	3-11
Materials ___________________ __________________________________________________ 3-13	3-11
Methods of application _________________________________________________________ 3-14	3-12
Precautions ... _____________ ___ ______________________________________________ 3-15	3-12
IV.	Inspection
Essential points of inspection _________________ _______________________________ 3-16	3-12
Methods of inspection ___________ . . ____________________________._____________ 3-17	3-12
Chapter 4.	REPAIR OF OTHER ITEMS
Section I. Basic repair
Cleaning ..	...	____________________________________________________________ 4-1	4-1
Straightening	_________________________________________________________________ 4-2	4—2
Soldering and	brazing__________________________________________________________ 4-3	4-5
Riveting _______________________________________________________________________ 4-4	4-7
Welding _____________________ __________________________________________________ 4—5	4—8
II. Repair of Components
Broken parts	. .	... __________________________________________________________ 4-6	4-9
Joints _________________________________________________________________________ 4-7	4-10
This manual supersedes TM 10-270, 26 January 1965.
Paragraph	Page
III.
Appendix A.
B.
Glossary .
Refinishing
Preparation	of	surface ._____________ ___________________________________ 4-8	4-11
Materials ___________________________________________________________________ 4-9	4-11
Methods of	application ______________________________________________________ 4-10	4-11
Inspection __________________________________________________________________ 4-11	4-11
REFERENCES .. _	______________________________________________ _____ A-l
INSPECTION CHECKLIST ________________________________________________________ _____ B-l
_____________________________________________________________________________ _____Glossary 1
CHAPTER 1
INTRODUCTION
1—1. Purpose
This manual is published as a guide for personnel
engaged in the repair of furniture, mess equip-
ment, tools, and implements. The instructions
listed are applicable for either mobile or fixed
repair units or installations.
1—2. Scope
a.	The manual discusses preliminary inspec-
tion of items, preparation of the items for re-
pair, repair procedures, and inspection of the
finished work.
b.	The manual covers the general procedures
to be followed in the repair of wood and metal
items and the repair of tools and implements.
1—3. Recommended Changes
Users of this manual are encouraged to submit
recommended changes or comments to improve
the manual. Comments should be keyed to the
specific page, paragraph, and line of the text in
which the change is recommended. Reasons will
be provided for each comment to insure under-
standing and complete evaluation. Comments
should be prepared using DA Form 2028 (Rec-
ommended Changes to Publications) and for-
warded direct to Commanding General, U.S.
Army Ordnance Center and School, ATTN:
ATSOR-INT, Aberdeen Proving Ground, Md.
21005.
1—4. Support Maintenance Activities
Consolidated support maintenance activities are
organized to fit the needs of a particular instal-
lation and are designed to provide flexibility in
repair operations. Such an activity may include
a clothing and textile repair shop, a footwear
and leather goods repair shop, a metal and wood
repair shop, a furniture repair shop, a heavy
tentage repair shop, a canvas and webbing re-
pair shop, an office machine repair shop, and
an airdrop equipment repair shop.
1-1
CHAPTER 2
REPAIR OF WOOD, PLYWOOD, AND FIBER ITEMS
Section I. BASIC REPAIR
2—1. General
a.	The variety of operations in the repair of
wood items is so great that not all of them can
be anticipated and discussed in this manual. The
success of a repair job depends, many times, not
on specific repair instructions for the article
being repaired, but on the repairman’s knowledge
of both hand- and power-operated woodworking
tools. The purpose, limitations, and operation of
each tool in the shop should be understood; and
the decision on how to effect a repair should be
made before the repair is begun. TM 5-461 and
TM 9-243 should be consulted for the proper use
of woodworking handtools, such as planes, ham-
mers, saws, and chisels. The various types of
woodworking machine tools, such as bandsaws,
jointers, surfacers, shapers, mortisers, and lathes
are covered in separate technical manuals. These
manuals should be consulted for woodworking
procedures involving the use of these machine
tools.
b.	The repairs covered in this chapter would
be done in the furniture repair shop within the
consolidated support maintenance activity at an
installation. A model layout of such a repair
shop is shown in figure 2-1.
2—2. Gluing
a.	General.
(1)	Whenever practicable, glue should be
used to repair broken tables, chairs, chests, and
other articles constructed of wood. Glue makes
a neat, strong, and durable repair. On side and
edge grain, glue is as strong as the wood it
holds; on end grain, however, additional support
is necessary, usually in the form of tenons and
dowel pins.
(2)	Satisfactory glue repairs depend on
such factors as the density and structure of the
wood, the presence of extractives or infiltrated
materials in the wood, and the kind of glue used.
Heavy woods are harder to glue than light woods;
hardwoods are harder to glue than softwoods;
and heartwoods are harder to glue than sap-
woods.
b.	Types of Glues. The following types of
glues are available for the repair of wood ar-
ticles :
(1)	Dry aoiimal glues. Dry animal glues
are made in flake or granular form. They are
easy to prepare and are usable at least 8 hours
after preparation. They are applied either by
hand or by a mechanical spreader. Both the wood
and the glue must be warm on application. The
glue begins to set almost immediately; therefore,
assembly time is kept under 5 minutes, and, if
possible, under 3 minutes. The work is cold-
pressed and the clamps are left on for at least
2 hours. Animal glues have practically no stain-
ing tendency and only a moderate dulling effect
on tools. These glues are very strong when kept
dry but weaken rapidly when exposed to mois-
ture. The best grade, fortified with a fungicide
to prevent mildew, should be used.
(2)	Liquid animal and fish glues. Animal
and fish glues are supplied in liquid form ready
for use and are applied cold by hand. Assembly
time is somewhat longer than that for dry ani-
mal glues but should not exceed 5 minutes. The
work is cold-pressed for 2 to 3 hours. Liquid
glues cause little or no staining and dull tool
edges only slightly. Better grades of these glues
have a moderate dry strength, but all grades
weaken rapidly when exposed to moisture. There-
fore, these glues should be used only where
moderate moisture conditions are to be expected.
(3)	Blood-albumin glues. Blood-albumin
glues are mixed at the time of use and applied
cold either by hand or by mechanical spreader.
The length of their working life varies, and the
manufacturer’s recommendations should be fol-
lowed. The assembly time should not exceed 5
minutes. Most blood-albumin glues require hot
pressing, which limits their use. They stain wood
slightly and have a moderate dulling effect on
tool edges. They are high in strength both when
dry and after exposure to moisture.
2-1
A. DeWalt saw
B. Table saw 10”
C. Mortiser
D. Jointer 8"
E. Jointer 6”
F. Planer
G. Sander disk
H. Sander spindle
I. Grinder
J. Lathe
K. Band saw
L Shaper
M. Gumming machine
N. Wall locker
0. Clamp rack
P. Round bin
Q. Buffer (portable)
R. Parts cabinet
S. Wall locker
T. Key cabinet
U. Drill press (portable)
V. Panelyte rack
W. Work bench
X. Paint agitator
Y. Air compressor
Z. Shelves
Figure 2-1. Model layout of a furniture repair shop.
(4)	Synthetic resin glues. The most com-
mon and successfully used types of synthetic
resin glues are as follows:
(a)	Urea resin glues. Urea resin glues
are prepared in both powder and liquid forms.
They are mixed with cold water and applied
either by hand or by a mechanical spreader.
Joints are either cold- or hot-pressed. For cold-
pressed joints, the pressure time is 4 hours. For
hot-pressed joints, the pressure time is 5 minutes
after the temperature at the glue line has been
raised to about 250° F. These glues stain wood
slightly and have a moderate dulling effect on
tool edges. They have a high dry strength and,
although more moisture-resistant than animal
glues, are not as resistant as the phenolic, re-
sorcinol, or melamine resin glues. Cold-setting
urea resin glues cannot be used if the tempera-
ture of the shop or the wood is below 70° F.
(b)	Phenolic, resorcinol, and melamine
resin glues. These resin glues are used on all
outside grades of plywood and on exposed gluing
assemblies because they have higher moisture
resistance than other glues. They are prepared in
both aqueous suspension and dry-film forms. Hot-
pressing is essential with both dry-film and aque-
ous forms. These glues have a moderate staining
effect and a moderate dulling action on tool
edges. They are recommended for any assembly
in which heat and pressure can be used to set
the glue. A joint properly made with these glues
is almost indestructible regardless of exposure
conditions.
(5)	Casein glue. Casein glue, or “cold wa-
ter” glue, is mixed fresh every day and used
cold. Temperature control and speed are not
necessary, since this glue does not begin to set
until 10 to 15 minutes after its application.
2-2
(V) BAR clamp
Figure 2-2. Various clamps used to apply pressure to glued joints.
Casein glue should be fortified with a fungicide
to prevent mildew. This glue is not as water-
resistant as the resin glues.
(6)	Other glues. Other ready prepared and
fast setting glues are also available.
c.	Rules for Gluing. Observe the following
rules when making glue repairs:
(1)	Do not sandpaper surfaces to be glued.
(2)	Before applying the glue, make certain
that the wood surfaces to be glued fit tightly
together and that all the old glue is removed.
(3)	Use a glue thin enough to run freely
from a full brush.
(4)	Apply pressure with one or more of the
various clamps provided for holding the parts
together until the glue sets (fig. 2-2).
(5)	Apply hand screws and clamps as
quickly as possible.
(6)	Use softwood blocks over finished sides
and edges to protect the surfaces from being
marred by clamps.
(7)	Apply only light pressure if the sur-
faces are well matched and the contact area is
small.
(8)	Apply pressure up to the crushing
strength of the wood when the glued area is
large. (Do not exert pressure beyond the crush-
ing strength of the wood.)
(9)	Apply pressure for at least 2 hours if
heat is not used.
(10)	Reduce pressure time when using hot-
setting urea, or phenolic, resorcinol, and mela-
mine resin glues. (The pressure time for hot-
setting glues may be reduced to 5 minutes or
less.)
(11)	When adjusting a wood clamp, use the
inner screw as a fulcrum, adjusting it to the work
first; then turn the outer screw to tighten the
clamp.
(12)	When several clamps are used, reverse
every other one to prevent warping and pulling.
d.	Additional Information. For additional in-
formation on adhesives or glues consult Military
Standardization Handbook—691-A.
2-3
Section II. REPAIR OF COMPONENTS
2-3. Warped Parts
Repair warped parts by reconstructing or
streightening.
a.	Reconstructing. Use a glued-up part in-
stead of a solid part. For example, if an 18- by
36-inch board is needed, glue up a board from
three 6-inch pieces or rip an 18-inch piece into
three 6-inch pieces and glue them together, in-
verting the center piece so that the grain
stresses are balanced (fig. 2-3).
SOLID BOARD
DOTTED LINES
SHRINKAGE TENDENCY INDICATED BY
©GLUED-UP CONSTRUCTION
BALANCED STRESSES
Figure 2—3. Method of repairing warped board by
ripping and gluing.
b.	Straightening. Straighten a warped part
by using one of the following methods:
(1)	Apply hot water to a piece of canvas
laid on the convex side of the warped part. Keep
the opposite side dry and allow free circulation
of air around the part being straightened. When
the wood has reached the desired degree of
straightness, place it in clamps or forms to hold
it into position until dry.
(2)	Place a wet pad on the concave surface
so that the wood fibers may absorb moisture
and expand. When the part is straight, clamp it
and let it remain overnight. A board moistened
to such an extent that it becomes warped in the
opposite direction may be brought back with an
application of hot sand on the convex surface.
2—4. Broken Parts
Replace broken parts with new parts. If replace-
ment is not feasible, repair the break in one of
the following ways:
a.	Double Wedge. Glue a snug-fitting double
wedge of hardwood into a mortise cut at the
point of the break (fig. 2-4). When the glue has
set, sand and refinish.
Figure 2-4. Repairing a break with a double wedge.
b.	Splints. When the broken part is too
slender to be repaired with a double wedge, cut
away the outer surface and apply splint (figs.
2-5). Glue the splints in place, sand and re-
finish.
Figure 2-5. Repairing a break with splints.
c.	Wood or Metal Backing. Where projecting
material does not interfere with the operation
or detract from the appearance of the article
being repaired, use wood or metal backing to
hold the broken parts together (fig. 2-6).
2-4
Figure 2-6. Repairing a break with, backing.
COMPLETED SCARF JOINT
Figure 2-7. Repairing a break by scarf splicing.
d.	Glue. Repair lengthwise breaks with glue.
Claimp the glued parts together and refinish
when dry.
e.	Scarf Splice. The scarf splice requires close-
fitting contact surfaces. Handtools can be used
with a simple jig (1, fig. 2-7) to insure ac-
curate work. With C-clamps, fasten the jig, the
guide, and the pieces to be spliced to the work-
2-5
bench. Cut the bevel by splicing, using a hand
plane, side down, against the edge of the jig
base. Glue and clamp the planed ends together
and refinish when dry (2, fig. 2-7).
2-5. Surface Parts
a.	Solid Surfaces. The repair procedure for
smoothing a damaged solid surface depends upon
the degree of damage. Determine the extent of
the damage and make the repair in accordance
with the following procedures:
(1)	Light scratches. On a varnished sur-
face, apply liquid amalgamator to the damaged
area; this softens the old varnish, causing it
to flow and level itself, after which it hardens
again.
(2)	Checking. Wash and thoroughly scrub
the checked ’ surface with a mild soap, using a
stiff-l&istled brush to remove all dirt from the
cracks. When dry, apply the amalgamator on
the surface like a thin varnish. After the amal-
gamator has dried, renew the surface by waxing
and polishing.
(3)	Shallow dents. A shallow dent may be
removed by one of the following methods:
(a)	Carefully remove the varnish cover-
ing the dent to bare the wood. Apply a few
drops of water to the bared wood; the water
will swell the compressed wood fibers so that
they will return to their original position.
(b)	If simply soaking does not remove the
dent, use heat. Moisten the wood as in (a) above.
After the water has penetrated the wood fibers,
place a pad over the dent and hold a hot solder-
ing iron on the pad (fig. 2-8). After the wood
has returned to its original position, stain it to
match the original finish and revarnish it. Fin-
ish when dry by applying amalgamator to blend
the edges of the new varnish into the old.
(c)	If neither of the above methods is
practical, remove the dent by sandpapering or
planing.
CAUTION
Use stick shellac in open air or in a
well-ventilated room.
(4)	Deep defects. If a defect is deep, clean
out the defect, removing all the loose or crushed
wood fiber. Enlarge it if necessary and undercut
the edges slightly. Fill defect with wood cement,
commonly known as stick shellac. Use stick shel-
lac of appropriate color to match the original
finish (cement from different colored sticks may
be blended together). Use a soldering iron to
soften the cement so that it will drop into the
defect (fig. 2-9). Care should be taken to see
that the cement is not heated to such a tempera-
ture as to become charred. The heat should be
just enough to make it flow without bubbling.
After filling the defect even with the surround-
ing surface, smooth the cement with a knife
blade which has been heated over an alcohol
burner. Do not use a candle or other flame to
heat the knife because soot from the flame will
ruin the cement. After the cement has hardened,
rub the surface with an oiled felt pad dipped in
Figure 2-8. Removing dents with a damp cloth and a
soldering iron.
2—6
Figure 2-9. Repairing surface defects with stick shellac and soldering iron.
rottenstone to remove the glaze. If a defect is un-
usually deep, first fill it to slightly below the
finish level with fresh plastic wood or sawdust
mixed with casein glue. After the filling has
dried, apply stick shellac to match the finish.
(5)	Extensive defects. If the surface is so
greatly damaged that none of the above pro-
cedures is practical, cover the entire surface with
plywood or composition board cemented down
with glue. First, remove the finish and sand-
paper the old surface until it is smooth and
free of irregularities. Cut the edges of the new
covering flush with the old top edge. If the old
edge is marred, use a thin wood banding of the
same wood and finish as that of the original
surface. Make sure the top edge of the banding
is flush with or just below the surface level of
the new top. Make the banding wide enough to
cover both the old edge and the new surface
material. A tempered prestwood surface need
not be finished.
(6)	Warped parts. For the repair of
warped parts, refer to paragraph 2-3.
b.	Veneered Surfaces. Repair veneered sur-
faces in the following ways:
(1)	Minor defects. Use stick shellac to re-
pair minor defects in veneered surfaces, observ-
ing the same procedure as that discussed in a(4)
above.
(2)	Small defective areas. If the damage
is confined to a small area, repair it with a
veneer patch slightly larger than the damaged
section. Apply three or four small spots of glue
to the damaged area. Press the patch over the
glue and allow it to set. With a sharp knife
held vertically, cut through both the patch and
the damaged veneer. This cut need not follow a
rectangle; it is better if tapered to a point. De-
tach the patch and clean out the damaged veneer
within the cut area. Apply glue, insert the patch,
and place a weight on it. After the glued patch
has set, remove the excess glue from the sur-
face and refinish.
(3)	Blisters. To repair loose or blistered
veneer, steam the damaged area to make the
veneer pliable. With a sharp knife cut the blister
open, apply glue, and press the veneer into place
again, working fast to get the job completed
before the veneer dries out and breaks. Squeeze
out the excess glue at the edges, wipe if off,
and place a weight on the reglued area. When
the glue has dried, finish the repair by sanding,
staining, and revarnishing.
2-6. Joints
a.	A badly worn joint, a fractured joint, or
any joint that cannot be successfully fastened
by glue alone may be repaired in the following
ways:
(1)	Bracing.
(a)	Brace with a woodblock (1, fig. 2-
10).
(b)	Brace with a wood crosspiece (2, fig.
2-10).
(c)	Brace with an iron strap (3, fig. 2-
10).
2-7
WOOD CORNER SPLINE
Figure 2-10. Methods of bracing.
(d)	Brace with an angle iron (4, fig. 2-
10).
(e)	Brace with a corner spline .(5, fig.
2-10).
(2)	Wedging.	'
(a)	If a tenon is rectangular, insert a
wedge in the edge of the tenon and angle-cut
the mortise to securely hold the wedged tenon
(1, fig. 2-11).
(b)	If a tenon is round, insert a wedge
in the end of the tenon and drive the tenon
back into place (2, fig. 2-11).
(3)	Fastening.
(a)	Fasten with a wood screw (.1, fig. 2-
12).	'
(b)	Fasten with dowels (2, fig.. ,2-12).
(c)	Anchor with a cross-screw or cross-
dowel (3, A and B, fig. 2-12).
b.	When it is not practicable to repair a frac-
tured joint by one of the methods in a above,
the joint in some cases may be reconstructed.
For example, to repair a broken tenon on the
‘ Fung of a chair (1, fig. 2-13), proceed in the
' Following manner:
’	(1) Saw off the broken tenon flush with the
ftenon shoulder (2, fig. 2-13).
(2)	Drill a hole in the rung (2, A, fig. 2-
13) and insert a dowel.
(3)	Bore out the socket to a size slightly
larger than it was originally and glue in place
a snug-fitting bushing (2, B, fig. 2-13).
(4)	Bore the bushing to receive a dowel
(2, B, fig. 2-13).
(5)	Apply glue to the dowel and the socket
and clamp the pieces together.
(6)	Finish by removing the excess dried
glue.
2—7. Fastenings and Attachments
Fastenings and attachments consist of locks,
2-8
Q WEDGING OPEN AND BLIND TENONS
2
WEDGING A DOWEL TENON
Figure 2-11. Methods of wedging.
catches, hinges, corner plates, strike plates,
knobs, handles, and other fittings, all commonly
referred to as hardware. If an article of hard-
ware is badly damaged or missing, replace it
with one similar to that used in the original con-
struction. Minor damage causing hardware to
loosen and become faulty in operation should be
repaired.
a.	Locks and Catches. When minor shrinkage
or warpage makes door locks and catches fail
to work properly, repair by shifting strike plates
or adjusting hinge positions.
b.	Loose Hardware. When screw holes or nail
holes become enlarged, causing hinges, strike
plates, latches, handles, and similar fittings to
loosen, fill the holes with plastic wood or insert
softwood plugs. Once the holes are plugged and
securely fastened, replace the fitting.
c.	Worn Areas Around Fitting. If wood sur-
faces around a fitting become badly worn, re-
move the fitting, inlay a piece of wood in the
worn area, and refasten the fitting. If this is
not practical, relocate the fitting. Use the follow-
ing method to relocate the butt hinge on a door
or on a lid:
(1)	Mortise the door or the lid to a depth
double the thickness of the hinge. This elimin-
ates the second mortise and reduces the chance
of an error in marking or mortising.
(2)	Fasten the hinge on the door or the lid.
(3)	Set the door or the lid in position and,
with a marker set in the hinge, press the hinge
against the frame. Drill a screw hole in the
frame at the point indicated by the marker.
(To make a marker, cut off a screw to a length
just long enough to project 1/16 of an inch
through the hinge. File the stub to a point
and set it in the hinge.)
2-9
PLUG
2 ) FASTENING A TENON JOINT WITH DOWELS
Q ANCHORING A TENON JOINT WITH A CROSS SCREW OR A DOWEL
Figure 2-12. Miscellaneous methods of fastening joints.
BROKEN DOWEL TENON
-~x RECONSTRUCTING DOWEL
TENON AND MORTISE
Figure 2-13. Replacing a broken dowel tenon.
2-10
2—8. Upholstery
Repairs needed on upholstered furniture consist
of recovering, replacement, or redistribution of
padding; replacement or refastening of webbing;
and regluing, reinforcing, or replacing frame
parts. With spring construction, replacing, an-
choring, and retying springs may also be neces-
sary.
a.	Cover. Replace the entire cover if the fabric
on the seat, back, or arms is torn, soiled, or worn
beyond repair. Since it usually is impossible to
match new fabric to worn or faded fabric, all
sections in most cases must be recovered when
one is damaged. Procedures for recovering up-
holstered furniture vary with furniture designs,
but the following general procedures apply to
most types:
(1)	Remove the old cover carefully, taking
out all tacks.
(2)	Remove the padding.
(3)	Overhaul the frame, the webbing, the -
springs, and the padding (b below).
(4)	Using the old cover as a pattern, cut
a piece of new material of the same size and
shape.
(5)	Smooth out and replace any lumpy or
torn padding.
(6)	Lay the new cover in place, making
certain that all four sides have the same amount
of surplus material.
(7)	Tack the center of opposite sides,
stretching the material lightly but firmly. Do
not drive the tacks- all the way in. Work from
the center to the edges, stretching the fabric
or material evenly. If wrinkles develop, remove
the tacks and work the wrinkles out. Note how
the old covering was folded and fitted at the
corners. If this was satisfactory, fit the new
cover the same way.
(8)	After the covering has been tacked to
the sides of the frame, cover the tack heads
with an edging or gimp. Fasten the gimp with
large-headed upholstery nails spaced about 2
inches apart.
b.	Padding. Padding of tow, cotton batting,
excelsior, or moss is used over the springs in the
case of spring construction, or on the webbing
in the case of padded construction. When the
padding shifts or becomes lumpy, remove the
cover and rearrange or replace the padding, us-
ing the following procedure:
(1)	Remove all the old padding and tack
a piece of burlap smoothly over the entire sur-
face to be padded.
(2)	Spread the padding evenly over the
burlap, forming a compact cushion about 1 1/2
inches thick.
(3)	Cover this with a second piece of bur-
lap or muslin, tacked down securely, and place
a 2-inch layer of cotton batting on top. Pull off
the surplus cotton around the edges; do not cut
the cotton, since this would make a ridge under
the cover.
(4)	Tack a cambric cover over the frame
bottom to keep the padding from working
through to the springs or the webbing and falling
out.
(5)	Replace the cover (a above).
c.	Frame. To repair a frame, use the same
methods as those used on ordinary furniture.
(1)	Loose frame joints. Repair loose frame
joints by one of the methods discussed in para-
graph 2-6.
(2)	Other frame damage. Repair other
frame damage by following the procedures dis-
cussed in paragraphs 2-3 and 2-4.
d.	Webbing. Whenever the covering is re-
moved, inspect the. webbing for signs of wear
or breakage. Replace the damaged webbing and
refasten the loose strips. Run the strips of webb-
ing crisscross (fig. 2-14). It is not necessary to
close the entire bottom with webbing, but to much
webbing is better than too little. If the springs
are to be anchored to the webbing, space the
webbing to support the spring bases. Similarly,
anchor metal strips or wood cleats and space
them properly for the springs.
Figure 2-1 If. Replacing webbing.
2—11
Figure 2-15. Methods of anchoring springs.
e.	Springs. Reanchor and retie shifted and
loose springs, straighten bent springs, and re-
place broken springs.
(1)	Anchoring. The method of anchoring
springs depends upon the material to which they
are fastened. When fastening springs to webbing,
use heavy flax cord about 1/8 of an inch in dia-
meter. Fasten the springs securely to the webbing
(1, fig. 2-15). Fasten each spring in three places.
At each point of fastening, secure the spring
with two stitches and tie the ends underneath;
if a spring is merely sewed round and round, it
will shift; if the twine breaks, the spring will
loosen entirely. When anchoring springs to metal
strips, use metal clamps. If clamps loosen, rerivet
them (2, fig. 2-15). When fastening springs to
wood cleats, use staples or metal straps and nails
(3, fig. 2-15).
(2)	Retying. After the springs are an-
chored, retie them with heavy flax cord, using
the following procedure:
(a)	Nail the cord to the center of one
side of the frame. Pull it over the top of the
springs to an opposite anchoring nail. Allow
enough cord to tie two double half hitches.
(6)	Bring the cord up to the top of the
first coil spring and tie it with a double half
hitch to the nearest rim of the first spring. Be-
fore drawing the knot tight, pull the spring down
to the shape of the seat or the back (fig. 2-16).
Continue to the opposite side of the top on the
same spring and tie it.
Figure 2-16. Springs tied in place.
Figure 2—17. Springs tied lengthwise, crosswise, and
diagonally.
(c)	Continue in like fashion, tying two
2—12
points on each spring and finally anchoring the
cord to the nail on the opposite side of the frame.
Run the cords in both directions (side to side
and front to back) at right angles to each other
until all the springs are tied in two directions.
(d)	Tie springs diagonally in the same
manner, beginning at one corner of the frame
and anchoring the cord on the opposite corner.
Section III.
2—9. Preparation of Surface
Before attempting to refinish a wood article, be
sure that the surface is smooth and free from
dirt, dust, and grease.
a.	Materials. The following materials are suit-
able for cleaning and smoothing wood surfaces:
(1)	Abrasives.
(a)	Disks, sanding. Sanding disks are
flat, circular pieces of sandpaper of various
types, sizes, and coarseness to be used with
motor-driven sanders. The disks are glued to the
rotating element.
(b)	Paper, flint, class B. Flint paper is
common sandpaper of crushed flint rock glued
to heavy paper sheets. Grain sizes range from
No. 4/0 to No. 3. No. 4/0 is used for sandpapering
wood and metal surfaces requiring an extra fine
finish; No. 2/0 for a fine finish; No. 1/2 for rub-
bing down undercoats of paint and varnish in
preparation for the final coat; and No 1 to No 3
for rubbing down old coats of paint when the
old coat of paint is in bad condition and must
be removed before repainting.
(c)	Wool, steel, commercial. Steel wool,
which is a fluffy or wool-like mass of steel turn-
ings or threads, is prepared in grades No. 00, 0,
1, and 3, ranging from extra fine to coarse. It
is a mild abrasive for rubbing down and smooth-
ing wood or for the removal of light rust from
metal before repainting.
(2)	Cloth, sponges, and waste.
(a)	Burlap, jute. Jute burlap is a coarse,
heavy, loose-woven, general-purpose cloth.
(b)	Osnaburg, bottom,, unbleached, class
B. Osnaburg (cloth, cotton, osnaburg) is a
coarse, heavy cloth used as a substitute for jute
burlap.
(c)	Cloth, wiping, cotton, type II, class A.
This is a cloth that is relatively free from lint.
It is used as a substitute for cotton waste, es-
pecially when lint deposits are undesirable; as a
substitute for sponges when washing wood and
metal work; and as an applicator for strong
(e) Repeat with the cord at right angles
to the first set of diagonal cords. Tie this cord
to the spring with two double half hitches and
to the other three cords at their junction in the
center of the coil. The finished work should show
each spring tied at eight places around the top
edge and at the point where the cords cross in
the center (fig. 2-17).
REFINISHING
soap, lyes, soda ash, or other alkaline solutions,
which cause sponges to deteriorate quickly.
(d)	Sponge, cellulose, coarse-pore, rec-
tangular. This is a synthetic sponge available in
sizes 6 and 10. It is not for use with solutions
containing soda ash, trisodium phosphate, or
caustic soda (lye).
(e)	Sponge, natural, unbleached, size E,
type III or type VIII. This is a natural material,
which has a large liquid-absorption capacity and
becomes soft when wet without losing its original
toughness. It is used with mild cleaning solutions.
It is not to be used with solutions containing
soda ash, trisodium phosphate, or caustic soda
(lye).
(/) Waste, cotton, white. This is a good
grade of cotton waste used for general cleaning.
(3)	Fluids.
WARNING
Acetone is toxic. Prolonged exposure to
its fumes will cause nausea, headache,
and eventually chronic illness. It should,
therefore, be used in the open air or in
a well-ventilated room and not near an
open flame. Acetone must be kept in a
tightly sealed container.
(a)	Acetone, grade B. Acetone is a clear,
colorless, volatile, flammable liquid. It has a
sweetish odor and is soluble in water and alcohol.
It is used in the preparation of paint and varnish
remover.
WARNING
Denatured alcohol is poisonous. It must
not be used near an open flame and must
be kept in a tightly sealed container.
(b)	Alcohol, denatured, grade 2. De-
natured alcohol is a clear, colorless, volatile,
flammable liquid. It is used in the preparation
of paint and varnish remover; as an emergency
substitute for paint thinner; as a solvent for
shellac varnish; as a cleaner for shellac varnish
brushes; and as „a liquid for cutting shellac.
2-13
WARNING
Ammonia fumes are very irritating to
the nose, throat, and lungs and should,
therefore, be used in a well-ventilated
place. If splashed in the eyes, wash the
eyes with large amounts of water. Fresh
air is the antidote for nausea. Ammonia
on the skin will cause smarting and
burning. The antidote is to wash the
area with water and apply petrolatum,
olive oil, lard, or similar greases or oils.
(c)	Ammonia, aqua A. C. S., grade B.
Aqua ammonia (ammonium hydroxide) is a
colorless solution of ammonia gas in water, con-
taining about 27 percent of ammonia by weight.
Ammonia must be kept in tightly sealed con-
tainers. Solutions in glass containers may de-
velop a slight cloudiness during prolonged pe-
riods, but this does not reduce the cleaning qual-
ities. Ammonia is diluted with water and used
for general cleaning purposes.
WARNING
Because of its flammable, explosive, and
toxic nature, benzol should be used in
the open air or in a well-ventilated
room and not near an open flame. It
must be kept in a tightly sealed con-
tainer. If it is absorbed into the body, it
will cause nausea, headache, extreme fa-
tigue, and anemia.
(d)	Benzol, technical (benzene, grade
C). Technical benzol (benzene, grade C) is a
clear, colorless, volatile, flammable liquid, having
an odor similar to that of gasoline. It is soluble
in alcohol, insoluble in water. Vapors of benzene
are heavier than air, with which it forms to
make explosive mixtures. It is used to remove
certain gum deposits from metal surfaces and
grease and oil spots from wood. It is also used
in the preparation of paint and varnish remover.
(e)	Remover, paint and varnish, type II.
Type II paint and varnish remover is a non-
flammable, organic solvent with suitable evap-
oration retarders. It is used for removing paint
and varnish from both metal and wood surfaces.
(4)	Miscellaneous.
(a)	Soap, castile, rvhite. Castile soap is a
neutral soda soap made from vegetable oils. It is
used in the preparation of soap-sponging solu-
tions.
(b)	Powder, scouring, type C. Scouring
powder is a cleaning powder which is mixed
with water and used according to directions on
the package. It is used for cleaning grease, oil,
and dirt from wood.
WARNING
Caustic soda is very harmful to the
body and clothing. Flush affected area
of body immediately with water for at
least 20 minutes. Get medical attention.
If taken internally, a large dose of vine-
gar or lemon juice should be given, fol-
lowed by butter, olive oil, or cottonseed
oil. Induce vomiting by drinking large
quantities of tepid water. Precautions
should be taken to prevent inhaling par-
ticles when handled in dry form.
(c)	Soda, caustic (lye). Caustic soda is
a highly corrosive substance which readily dis-
solves in water. Solutions should be kept in con-
tainers of iron or glass. Caustic soda is used to
prepare, paint remover and to quicken the action
of other cleaning solutions. Caustic soda is not
to be used on aluminum or galvanized items.
b.	Procedure. Observe the following procedure
when preparing a wood surface for refinishing:
(1)	Cleaning.
(a)	Remove the loose dirt with a rag or
brush.
(b)	When dirt cannot be brushed loose,
sponge the surface with a soap solution.
(c)	Use benzene to remove grease and oil
spots.
(2)	Removing oil finish.
(a)	Apply enough paint and varnish re-
mover to completely soften the old paint and
varnish.
(b)	Scrape off the softened material with
a hand scraper, scraping with the grain.
(c)	Wipe the wood with a cloth dipped
in turpentine to remove the wax deposited by
the paint and varnish remover.
(d)	Smooth the stripped surface with
sandpaper or steel wool.
(3)	Sandpapering.
(a)	Always sandpaper with the grain;
scratches across the grain show badly through
a finish.
(b)	Sandpaper flat surfaces with the
sandpaper wrapped around a softwood block.
(c)	Sandpaper concave surfaces with the
sandpaper wrapped around a rounded stick or
half-round file.
(d)	Sandpaper convex surfaces holding
the sandpaper in the hollow of the hand.
(e)	Do not 'sandpaper surfaces to be
glued; the perfectly flat surface required for
gluing can be produced only with an edge tool.
(/) Begin sandpapering usually with a
coarse grade of sandpaper such as No. 1 and
finish with a fine grade such as No. 2/0.
2-14
2—10. Materials
a.	General. Wood furniture will be refinished
in its original color. As an alternate method,
laminated thermosetting plastic sheets (top) in
matching wood grain color can be used. Lami-
nated plastic sheets will meet all specifications
and tolerances as set forth in applicable military
or Federal specifications. Items so repaired will
retain the current Federal stock numbers and
identifications. Exceptions to the above are those
items requiring repairs to the extent that the
cost of refinishing in original color would be
prohibitive. Such items may be refinished in
color chip No. 26134 gray*, semigloss, and lami-
nated thermosetting plastic sheets (top), ap-
plied where required, providing such repairs are
within the permissible expenditure limitations.
General office wood furniture refinished in gray
will be designated nonstandard. The materials
described below are to be used when refinishing
a wood item. The item should be refinished with
the same kind of material as that used in the
original finish. If a different finish is desired,
all the old finish should be removed before the
application of a new finish.
b.	Paint.
(1)	Before beginning to repair a paint
finish, apply a priming coat (aluminum paint is
excellent) to the surface of the item. After the
priming coat has dried, apply the paint finish,
using either a brush or a spray gun. Two coats
of finish are usually enough for a good solid color.
(2)	On porous wood such as ash, chestnut,
and oak, use a wood filler mixed to a heavy con-
sistency (table 2-1). Cover knots with a clear
coat of shellac or, preferably, aluminum paint.
c.	Enamel. If the wood to be given an enamel
finish has pores larger than those of birch, apply
natural wood filler before beginning the repair
work. Touch up all bare areas with enamel un-
dercoater and sandpaper them when dry with
No. 5/0 and No. 8/0 sandpaper. After the surface
has been smoothed, apply the enamel (two coats if
necessary) over the entire surface. The enamel
may be applied with either a brush or a spray
gun.
d.	Lacquer. If the surface to be finished has
been treated with oil stain, paste-wood filling,
varnish, or paint, apply a tin sealing coat of
shellac. After the shellac has dried (at least 4
hours should be allowed for drying), rub it down
with No. 2/0 steel wool and apply the lacquer.
The lacquer (two coats usually are sufficient)
may be applied with either a brush or a spray
gun. If the area to be finished is small, a brush
•See Federal Standard 595A for complete Color Chart.
is more practical. Since lacquer dries very
quickly, care should be taken in brushing to avoid
lap marks.
Table 2-1. Filler Mix Required for Various Woods
Wood	Filler mix
Ash __________________________________ Heavy
Basswood______________________________ None
Beech ________________________________ Thin
Butternut ____________________________ Thin
Cedar ________________________________ None
Cherry _______________________________ Thin
Chestnut ----------------------------- Heavy
Cypress ______________________________ None
Fir __________________________________ None
Gum __________________________________ Thin
Locust _______________________________ Heavy
Mahogany _____________________________ Medium
Maple_________________________________ Thin
Oak___________________________________ Heavy
Orientalwood _________________________ Medium
Pine _________________________________ None
Poplar ________________________:______ None
Rosewood______________________________ Medium
Sycamore______________________________ Thin
Teak _________________________________ Heavy
Tanquile _____________________________ Heavy
Walnut________________________________ Medium
Zebrawood_____________________________ Medium
e.	Varnish. Varnish may be applied either on
wood in its natural color or on wood that has
been stained. If the wood has been oil-stained,
apply a coat of wood sealer before applying the
varnish. If a smooth surface is desired, whether
on wood in its natural color or on wood that
has been oil-stained, apply a wood filler before
applying the varnish. The varnish may be ap-
plied with either a brush or a spray gun.
f.	Stains.
(1)	To obtain a natural finish, color new
wood slightly with oil stain made from painter’s
tinting colors. Stain bare areas to match the old
wood, using the same stain as that in the original
finish. After applying water stain, sandpaper the
wood lightly. On wood with pores larger than
those of birch, apply wood filler after staining,
using filler of the same color as that of the orig-
inal finish. Color natural finish by adding oil
stain or painter’s tinting colors.
(2)	Apply stains by brushing, dipping, or
spraying (or, in repair work, by mopping with
a clean rag or cotton waste). Allow the oil
stains to remain on the surface a few minutes
before wiping off the excess. Staining should be
done quickly so that all laps may be picked up
while their edges are still wet.
g.	Wood Filler.
(1)	To obtain a smooth surface, use wood
filler preparatory to the application of paint,
enamel, varnish, lacquer, or stains.
2-15
(2)	Apply wood filler with a brush. After
the filler has remained for a few minutes, wipe
off the excess with burlap, clean rags, or cotton
waste, stroking first across and then along the
grain of the wood (table 2-1).
h.	Undercoaters and Sealers. Enamel under-
coater, paint primer, aluminum paint, and shel-
lac, as well as varnish and wood sealer, are used
as bases for glossy finish paint and enamel finish.
They are also used on concealed wood surfaces,
such as the undersides of table tops, the backs
of side panels, and the insides of drawers, to
protect against the changes in moisture content
of the air and to minimize the tendencies to
warp. When used other than as a base coating,
two coats (applied with either a brush or a spray
gun) should be used.
2-11. Methods of Application
The methods generally used in the application of
finishing materials are the brush method and the
spray gun method. For further information on
the application of finishing materials, refer to
TM 5-618.
2-12. Inspection
a.	Initial Inspection. When making the initial
inspection on wood items, use the checklist in
appendix В for guidance.
b.	Repairing the Item. After inspecting and
noting the amount of damage, repair the item.
If no special instructions are given, repair the
damage in accordance with the methods illus-
trated in paragraphs 2-1 through 2-11. Make
the repairs in the following order :
(1)	Repair broken parts.
(2)	Repair broken joints.
(3)	Secure loose joints.
(4)	Replace damaged or missing hardware.
(5)	Tighten loose hardware.
(6)	Repair surface damage.
(7)	Prepare surface for refinishing.
(8)	Apply finishing material.
c.	Final Inspection. Upon completion of re-
pairs, give the article a final inspection to make
sure that the following conditions have been met:
(1)	The species of wood used for replaced
parts is similar to that used in the original con-
struction.
(2)	All joints have been properly repaired
and braced sufficiently to withstand hard use.
(3)	No hardware is loose, damaged, or
missing.
(4)	Complementary hardware, such as
locks and strike plates, is in proper alinement
and functions smoothly.
(5)	All hardware has been properly fast-
ened, screws countersunk, and metal surfaces
freed of sharp silvers.
(6)	Components fit properly, stationary
parts fit with precision, and movable parts func-
tion without sticking or jamming.
(7)	All surface defects have been repaired
and sandpapered.
(8)	The proper finishing material has been
applied and there are no sandy spots, orange-peel
effects, or skips in the covering.
2-16
CHAPTER 3
REPAIR OF TOOLS AND IMPLEMENTS
Section I. BASIC REPAIR
3-1. Responsibility
The general repair of handtools and implements
is a responsibility of the using organization. Such
repair includes shaping, sharpening, straighten-
ing, and replacing and finishing handles.
3-2. Cleaning
All dirt, grease, corrosion, and rust must be re-
moved from tools and implements before any
repairs are attempted.
a.	Cleaning Materials. In addition to the ma-
terials discussed in paragraph 2-9, such as ben-
zol, caustic soda, cotton waste, paint and varnish
remover, and sponges, the following materials,
specially designed for cleaning metals, should be
used.
(1)	Abrasives.
(a)	Cloth, abrasive, aluminum oxide.
Aluminum oxide abrasive cloth is natural emery
or artificial aluminum oxide abrasive on cotton
drill or jean cloth. Grade 2/0 and finer grades
are used for polishing, while grade 0 and other
coarser grades are used for the general prepara-
tion of metal surfaces for painting.
(b)	Cloth, crocus. Crocus cloth is a fine,
soft, red, or reddish-brown powder (tripoli or
iron oxide) on cotton drill or jean cloth. It is used
for producing a fine finish on metals.
(c)	Cloth, emery. Emery cloth is the
same as aluminum oxide abrasive cloth de-
scribed in (a) above.
(d)	Paper, abrasive, aluminum oxide,
production-type. Production-type aluminum ox-
ide abrasive paper is similar to aluminum oxide
abrasive cloth, but has a special construction
and type of grain to provide a more rapid cutting
action. It is used with a solvent for the wet-
sanding of bare metals preparatory to painting.
(e)	Paper, abrasive, artificial, water-
proof, silicon carbide. This abrasive is a silicon
carbide on a strong, waterproof paper backing.
It is available in various grain sizes and consists
chiefly of finer grades than aluminum oxide
abrasive cloth. It is used for wet-sanding metal
surfaces where fine finishes are desired. Water
must be used with this abrasive in connection
with the sanding operation.
(2)	Fluids.
(a)	Conditioner, metal, acid, phosphoric,
concentrated.
1.	Type I—wash-off type. Type I acid
metal conditioner is diluted phosphoric acid con-
taining water-soluble, nontoxic grease solvents.
It is diluted with water and used as a dip applica-
tion for the removal of rust and for the prepara-
tion of metal surfaces for painting. It must be
washed off with water, preferably hot water.
2.	Type II—wash-off type. Type II acid
metal conditioner is similar to type I, but the
acid concentration is much less. It is diluted with
water and applied with a swab or brush for the
removal of rust and for the preparation of metal
surfaces for painting. It is removed by wiping
with dry or dampened rags.
WARNING
The use of a drycleaning solvent with-
out gloves will dry the skin and may
cause slight irritation. The antidote is
to rub grease or oil into the skin to re-
place the natural oils.
(b)	Solvent, drycleaning. This solvent,
known as Stoddard solvent and as petroleum
distillate solvent, is a colorless, flammable liquid
distilled from petroleum. It is used to clean metal
surfaces and to remove oil and grease spots from
wood and upholstery. It is not to be used near
an open flame. It evaporates quickly without
leaving a corrosion-inducing film on metal sur-
faces.
(3)	Compounds.
(a)	Compound, cleaning, alkaline. Alka-
line cleaning compound is a granular, solid com-
pound, soluble in water. It is used to remove
grease, tar, paint, etc, from metal surfaces. It is
not to be used on aluminum or zinc.
(b)	Compound, paint-stripping, alkali-
type. This compound, which is soluble in water,
3-1
is used for removing paint, lacquer, and enamel
from metal surfaces. It is not to be used on alum-
inum. A hot solution is made from 3 pounds of
compound to each gallon of water and applied by
flow, trickle, or brush method.
(4)	Miscellaneous.
(a)	Polish, metal, paste, type III. Type
III metal polish is an iron oxide base paste of
fine consistency and mild abrasive action. It is
used for polishing metal surfaces.
CAUTION
Solutions containing soda ash will at-
tack aluminum and remove galvanized
finishers.
(b)	Ash, soda, type I. Type I soda ash,
also called sodium carbonate, is a white, odor-
less, alkaline powder. It is soluble in water but
not in alcohol. It is used to remove grease and
oil preparatory to painting.
b.	Cleaning procedure. Use the following pro-
cedure to clean ferrous metals:
CAUTION
The following method of chemically
cleaning steel surfaces is not orginarily
used on polished surfaces. Acids and
similar materials not only dissolve the
rust but also attack the steel itself. In
case it is necessary to use chemicals,
care must be taken to remove every
trace of the acid from the surface of
the metal; otherwise, corrosive action
beneath the protective finish may be
accelerated later. The use of acids or
other chemicals to remove rust should
not be attempted unless authorized for
the items being cleaned.
(1)	Remove heavy dirt and loose soil with
a wire brush.
(2)	Use a wiping cloth soaked in dryclean-
ing solvent to remove grease and oil, making
certain to wipe the surfaces dry afterward.
(3)	Use abrasives or other mechanical
means to remove surface rust.
(4)	If the rust has progressed to such an
extent that pits are formed, use acids or specially
prepared compounds.
3-3. Straightening
Bent tools and implements should be straight-
ened before other repairs are attempted. Small
parts, such as screwdriver shanks, should be
squeezed in a vise. Heavy solids and large flat
surfaces should.be hammered on a flat block or
on an anvil. For information on the straighten-
ing of sheet metal, refer to paragraph 4-2.
3—4. Shaping and Sharpening
Grinding wheels, oilstones, grindstones, strops,
and files are used for shaping and sharpening
damaged tools and implements (fig. 3-1). A
grinding wheel (1) is used for reshaping worn-
away edges, for removing nicks and mushroomed
ends, and for restoring cutting-edge bevels. An
oilstone (2) or a grindstone is used for fine-
finishing a reground edge and for sharpening
tools not badly dulled. A strop (3) is used for
producing a very fine edge. A file (4) is used for
turning over the scraper edges and for sharpen-
ing saw teeth.
a.	Grinding Wheels. The grinding wheel gen-
erally is used in the initial stages of sharpening
tools and implements. When fine-edged tools are
being sharpened, the grinding wheel is used only
when the edges are badly nicked or bevels so
badly worn that sharpening by oilstone or grind-
stone is impractical.
(1)	Grades. Abrasive wheels generally are
graded as hard or soft. Wheels that shed parti-
cles slowly are known as hard; wheels that shed
particles easily are known as soft. Manufacturers
specify the grades of their wheels by numbers or
letters, usually with the lower numbers or letters
identifying soft wheels and the higher numbers
or letters identifying hard wheels.
(2)	Wheel selection. Selection of the proper
wheel depends upon the materials on which the
wheel is to be used and on the line of contact
between the work and the wheel. In general, it
may be said that a soft wheel is preferred for
grinding tools and implements. A soft wheel, al-
though it wears away somewhat faster, has less
tendency to heat the work and thus is prefera-
ble.
(a)	Hard materials, such as cast iron,
most of the alloy steels, and hardened steel, re-
quire sharp cutting edges. Therefore, a soft wheel
which sheds particles more easily under cutting
pressure, exposing new sharp particles, is used
for grinding harder materials.
(b)	Unhardened carbon steel and un-
treated machine steel can be ground to a satis-
factory finish with a cutting wheel too worn to
produce an acceptable finish on harder materials;
therefore, a wheel somewhat harder, a medium-
grade wheel which will retain its cutting parti-
cles longer, may be used on soft steels.
(c)	Softer materials, such as brass,
bronze, copper, and hard rubber, exert less pres-
sure against the wheel than soft steel; therefore,
a soft wheel should be used. A hard wheel would
fuse the chips, become clogged and glazed, and
heat the work.
(rf) The more narrow the line of contact
3—2
Figure 3-1. Methods of shaping and sharpening.
between the work and the wheel,
the harder the
wheel must be.
(3)	Aluminum oxide and silicon carbide
wheels. A general rule is to use silicon carbide
abrasives only for materials of low tensile
strength, regardless of their hardness, and use
aluminum oxide for materials of high tensile
strength, such as steels (table 3-1).
(4)	Dressing. With use, an abrasive wheel
loses its cylindrical shape. For precision grinding,
the wheel must be trued with a dressing tool. The
tool is held on the machine in such a way that it
travels across the face of the wheel, the tool being
tilted so as to wipe across its face rather than dig
into it. Moving the dressing tool too rapidly across
Table 3-1. Wheels and Materials
Wheel	Material
Aluminum oxide___________ Alloy steels
Annealed malleable iron
Carbon steels
High speed steels
Rough and hard bronzes
Wrought iron
Silicon carbide _________ Aluminum and copper
Brass and soft bronze
Cemented carbides
Gray and chilled iron
Rubber and leather
Very hard alloys
the face of the wheel cuts a spiral or thread in the
wheel which will produce a mottled or frosted ap-
pearance on the work and spoil the finish. Light
3-3
cuts should be taken with the dressing tool, no
more of the wheel being cut away than is neces-
sary.
(5)	Precautions. Take special precautions
when grinding the cutting edges of tools and im-
plements. Rapid grinding withdraws the temper
in steel through the heat caused by friction.
Careless grinding leaves cutting edges too thin
to withstand normal usage. When grinding tem-
pered tools and implements observe the following
rules:
(a)	Do not use a high-speed grinding
wheel.
(b)	Keep the fingers near the grinding
edge while grinding to determine whether the
material is becoming too hot.
(c)	Cool the material in water at fre-
quent intervals.
(d)	Grind cutting edges to the angle pre-
scribed in the original specifications.
(e)	Use the grinding wheel tool holder
for precision grinding and set it at the proper
angle.
(/) Wear goggles when using any grind-
ing machine.
(g)	Never grind on the side of the grind-
ing wheel.
b.	Oilstones. After a tool or implement has
been ground on a wheel, it may be whetted on
an oilstone in order to remove the wire edge and
the fine scratches made by the wheel. A tool or
implement with the edge in good condition and
not nicked may be sharpened by being whetted
only.
(1)	Grades. Oilstones are of three grades:
coarse, medium, and fine. The coarse and the
medium stones are used on badly dulled edges.
The fine stones are used for woodworking tools
and for classes of tools requiring a fine cutting
edge.
(2)	Shapes. Oilstones are of various shapes,
those with round edges being known as slip
stones.
(3)	Methods of using. When using an oil-
stone, always keep it moistened with a clean light
oil. When sharpening a beveled edge, place the
bevel flat on the stone, holding the stone sta-
tionary and moving the beveled edge over the
surface of the stone in either a circular or a
figure-eight motion. When sharpening a concave
edge, such as the inside edge of a gouge, hold
the tool stationary and rub a slip stone along the
edge. When sharpening a thin or knife-type edge,
hold the blade at 20° angle and draw it over
the stone (cutting edge leading), turning the
blade over on the blackstroke.
c.	Grindstones. Grindstones generally are used
to sharpen tools other than those with a fine
edge. The ax, mattock, and similar tools can be
sharpened by use of the grindstone. Water is
used on the grindstone for lubrication of the
surface and to keep tools and implements from
overheating.
d.	Strops. To remove a fine wire edge and to
accomplish additional sharpening, strop the tool
or implement on leather, canvas, or a smooth
woodblock.
e.	Files. Files generally are used to sharpen
saw teeth, auger lips and nibs, and scraper edges.
Both single-cut and double-cut files are used, the
most common shapes being flat and triangular.
For draw filing, the single-cut file is preferred;
for other types of filing, the double-cut is pre-
ferred. Coarse files are never used on hard steel;
only second-cut or finer prove satisfactory.
3—5. Procedures for Shaping and
Sharpening
The type of tool and its use will determine the
shape of its head or blade and the bevel of its
cutting edge.
a.	Saw Sharpening. To keep saw teeth in top
condition, touch up (dress) the teeth with a file
occasionally. A triangular, tapered file norm-
ally is used for handsaws. Under usual condi-
tions a saw may be sharpened with a file four or
five times before it needs a complete sharpening
and setting job. Sharpening a saw consists of
four major steps: jointing, shaping, setting, and
sharpening.
(1)	Jointing. Jointing consists of cutting
the points of the highest teeth down to the level
of the lowest points, so all teeth will cut equally.
Secure the saw in a vise; then place a mill file
on the teeth points of the saw, move it lightly
over the saw teeth from heel to toe, without
rocking the file, until all teeth are the same
height. Remove as little metal as possible for
this operation so as to minimize unnecessary re-
moval of metal.
(2)	Shaping. Saw teeth are shaped only
when they are evenly spaced and shaped.
(a)	Place the saw in the vise so that the
gullets of the teeth are about 1/4 inch above the
edge of the vise jaws.
(b)	Place a tapered, triangular file in a
file holder, then place the file in the first gullet
at the saw handle end (heel). This serves as a
guide as the teeth at the heel are seldom used.
Hold the file snugly in the gullet at a right
angle to the saw blade and file each tooth to its
original shape, making sure the bases of the
gullets are uniform and in a line parallel to the
3-4
points of the teeth. The file must be held at a
right angle to the saw and parallel to the floor,
because saw teeth are not beveled during the
shaping operation.
(3)	Setting. Setting is accomplished by
bending the teeth slightly with a saw set. To
effectively use the saw set, adjust it so the saw
teeth will be bent to their original angle. The
correct set usually can be found on the teeth
next to the heel, as they are relatively unused.
Place the saw blade in the saw vise so that the
first tooth at the heel is bent away from the
centerline of the saw blade. Put the saw set over
this tooth, positioning the anvil behind the tooth
and the plunger in front of it. Press the saw set
handles together so the plunger pushes the tooth
against the anvil to set the saw tooth. Release
the grip of the saw set, skip the next tooth,
and apply the same operation to the third tooth.
Proceed along the saw blade, setting every other
tooth in the same direction. Turn the saw around
in the vise so it faces the opposite direction. Bend
the alternate (unset) teeth in the same way, so
the teeth are alined in two even rows (fig. 3-2).
triangular file is held at the same bevel angle
as a comparable gullet in the little-used teeth
near the saw’s heel.
(a)	For the crosscut saw, the file will be
held at a 45° to 60° angle to the saw blade, re-
taining a horizontal or a 5° to 10° off-horizontal
level (1, fig. 3-3).
(b)	On a ripsaw, each tooth is filed at a
right angle (90°) to the saw blade. This provides
sharp square edges like a series of little chisels
in two parallel rows that overlap each other
(2, fig. 3-3). After every other tooth of the saw
has been sharpened, turn the saw around and
proceed to sharpen the opposite side of the saw
blade, following the same procedure. When filing
saw teeth, always keep in mind that the file
should cut only on the movement away from
the worker. The file should be raised clear of
the saw teeth on the return movement.
TOP VIEW
Figure 3—2. Comparison of crosscut and ripsaw
(showing alinement of teeth).
Q CROSSCUT SAW ANGLE OF FILING
ONE INCH
(4) Sharpening. To sharpen handsaws,
place the saw in the vise with the gullet bases
about 1/16 inch above the vise jaws and the saw
handle to the worker’s right. Place the file in
the gullet to the left of the first tooth set to-
ward the worker. Adjust the file holder so the
«—514 POINTS PER INCH-»
4'/2 TEETH
(T) RIPSAW ANGLE OF FILING
Figure 3-3. Saw setting and sharpening.
3-5
b.	Additional Information. For additional in-
formation on shaping and sharpening of tools
refer to TM 5-461 and TM 9-243.
3-6. Heat treating
a. General.
(1) Steel is iron that contains carbon in
any amount up to 1.7 percent (table 3-2). Since
subjection to heat is one phase of the process
used in the production of steel, an accurate
knowledge of heat treating is necessary in the
repair of steel tools and implements.
Table 3-2. Approximate Carbon Content of Certain Steels
Carbon content
Steel	(percentage)
Axle ________________________________________ 0.40
Cold chisel _________________________________ 0.75
Forging _____________________________________ 0.30
Gear	________________________________- -	0.35
Hammer_______________________________________ 0.65
Lathe	tool __________________________--	1-10
Machinery ___________________________________ 0.35
Metal file___________________________________ 1.25
Metal tool __________________________________ 0.95
Pipe ---------------------------------------- 0.10
Rail__________________________________--	0.60
Saw for steel _______________________________ 1.55
Saw for wood_________________________________  0.80
Setscrew ____________________________________ 0.65
Shaft --------------------------------------- 0.50
Spring ______________________________________ 1.00
Steel for stamping___________________________ 0.90
Tubing -------------------------------------- 0.08
Wood-cutting tool ___________________________  1.10
(2)	Heat treating is the heating and cool-
ing of steel in the solid state. By controlling the
rate of the heating temperature, the degree of
the final temperature (table 3-3), and the rate
of the cooling temperature, steel can be softened
or hardened as required for a particular opera-
tion.
b.	Types of Steel. Listed below are several
types of steel used in the repair of tools and
implements.
(1)	Austenite. Austenite is an exceedingly
tough steel but not as hard as other steels.
(2)	Martensite. Martensite is the hardest
and most brittle type of steel.
(3)	Troostite. Troostite is a steel almost as
hard as martensite but noticeably less brittle.
(4)	Sorbite. Sorbite is a steel with less
hardness than troostite but with added tough-
ness.
(5)	Pearlite. Pearlite is an annealed steel,
which is easily machineable.
c.	Types of Treatment. By being heated,
quenched, and in some instances drawn, steel of
any degree of ductility or hardness can be pro-
Table 3-3. Color Chart for Steels at Various
Temperatures
Temperature
Color	(degrees	F.)
Faint red ___________________________________ 900
Blood red _________________________________ 1,050
Dark cherry ______________________________  1,075
Medium cherry _____________________________ 1,250
Cherry or full red_________________________ 1,375
Bright red_________________________________ 1,550
Salmon ____________________________________ 1,650
Orange ____________________________________ 1,725
Lemon _____________________________________ 1,825
Light yellow_______________________________ 1,975
White _____________________________________ 2,200
Dazzling white_____________________________ 2,350
duced. The following types of treatment are com-
mon in the heat treating of steel.
(1)	Annealing. Metals which have been
rolled, drawn, hammered, or forged, or which
have been hardened by heating and quenching
can be made soft and ductile by annealing. An-
nealing is heating to a temperature of about
100° F. above the critical temperature range
(table 3-4) and cooling slowly in a confined
space. Annealing is also used to change the struc-
ture and toughness of the metals and to remove
any gases. Steel, when annealed, can be worked
into any shape desired.
Table 3-lf. Critical Temperatures for Various Carbon
Steels*
Temperature
Percentage of carbon	(degrees F.)
0.10 _________________________________________ 1,675-1,760
0.20 _________________________________________ 1,625-1,700
0.30 _________________________________________ 1,560-1,650
0.40 _________________________________________ 1,500-1,600
0.50 _________________________________________ 1,450-1,560
0.60 _________________________________________ 1,440-1,520
0.70 _________________________________________ 1,400-1,490
0.80 _________________________________________ 1,370-1,450
0.90 _________________________________________ 1,350-1,440
1.00 _________________________________________ 1,350-1,440
1.10 _________________________________________ 1,350-1,440
1.30 _________________________________________ 1,350-1,440
1.50 _________________________________________ 1,350-1,440
1.70 _________________________________________ 1,350-1,440
♦Cool slowly to anneal; cool i-apidly to harden.
(2)	Hardening.
(a)	The property of steel which causes
it to harden when heated and rapidly cooled is
associated with the physical changes of iron.
When heated, the iron undergoes a transforma-
tion in passing through a critical temperature
point (about 1,350° F.), changing from a form
which has a low solubility for carbon to a form
which has a high solubility for carbon. Upon
cooling, the reverse transformation occurs; but
since the changes are progressive and require
time for completion, they may be arrested if the
rate of cooling is increased.
3-6
(b)	If the cooling is very rapid, as in
water quenching, the transformation takes place
at a temperature (400° to 600° F.) very much
below the critical temperature point and the
carbon is held in a forced and finely divided
state, with the result that the steel becomes hard
and brittle and a great deal stronger than slowly
cooled steel. Increasing the carbon content in-
creases the degree of hardening possible for a
given cooling rate.
(c)	Alloy additions alter the rate of trans-
formation on cooling and permit deeper hard-
ening, with less severe rates of cooling. Since,
however, each alloy or combination of
alloys shows individuality in its effect, alloy
steels are made up and heat treated with a view
to the specific properties required for the struc-
tures for which they are to be used.
(3)	Tempering. When a steel is hardened by
quenching it is too brittle for ordinary pur-
poses; therefore, some of the hardness must be
removed by reheating the steel to a temperature
lower than the critical temperature and quench-
ing again. This process is known as' tempering
or drawing. It is not necessary to quench after
reheating, provided the correct tempering tem-
perature (table 3-5) has not been exceeded.
d.	Procedure. Desired results in the heat
treating of steel may be attained by heating
and quenching alone, or by heating, quenching,
and drawing.
(1)	Heating and, quenching. If steel with a
carbon content of 0.85 percent, for example, is
heated to 1,350° F. and then quenched in very
cold brine, austenite is formed; if heated to
1,350° F. and quenched in cold water, marten-
site is formed; if heated to 1,350° F.
and quenched in oil, troostite is formed; if heated
to 1,350° F. and quenched in a molten metal bath,
sorbite and pearlite are formed. This procedure
shows that the rapidity of cooling affects the final
structure of the steel. Quenching methods and
quenching materials, therefore, have much to do
with the type of steel desired.
(2)	Heating, quenching, and drawing. The
same results as those above can be obtained by
the following procedure: First heat the steel
(again taking 0.85 percent carbon content steel
as an example; to 1,350° F. and quench it in
cold brine to form austenite. Then, if martensite
is desired, reheat to 400° F. and cool; if troostite
is desired, reheat to 600° F. and cool; if sorbite
is desired, reheat to 800° F. and cool; if pearlite
is desired, reheat to 1,000° F. and cool.
e.	Precautions. Successful heat treating of
steel necessitates several precautions.
(1)	Heating.
(a)	Control the rate of heat to prevent
cracking of thick and irregular sections.
(b)	Heat until the desired temperature of
the article is uniform throughout.
(c)	Do not overheat the article; when
steel is heated close to its melting point, certain
elements are burned out and the grain of the
steel becomes coarse. In general, the lower the
carbon content, the higher the temperature to
which steel can be heated without being burned.
(d)	Do not judge the temperature of the
steel by its color when accurate temperature mea-
suring instruments are available.
(2)	Quenching.
(a)	Move the article around in the bath
to prevent warping and cracking.
(b)	Quench the article in a position that
will cool all of its parts uniformly; immerse
shafts vertically.
(c)	When using a water quench, keep the
temperature of the water at 70° F. to prevent
warping and cracking the steel.
(d)	Use salt brine (10 percent solution
of ordinary salt in water) where a comparatively
rapid cooling rate is necessary, as in the case of
carbon steel.
(e)	Use an oil quench to reduce warping
and cracking in cases where maximum hardness
is needed.
Table 5-5. Color Cha/rt of Various Tempering Temperatures of Carbon Steels
Color	Temperature (degrees F.)	Use
Faint straw		400	
Dark straw		460	Scrapers; hammer faces; lathe, shaper, and planer tools.
Very deep straw		480	Taps and dies
Brown yellow		500	Punches and dies; knives and reamers.
Bronze or brown purple		520	Drift pins
Peacock or full blue purple 		540	Augers; cold chisels for steel
Bluish purple		550	Axes; cold chisels for iron; screwdrivers; springs
Blue 		570	Saws for wood
Full blue		590	
Very dark blue		600	
Light blue 		640	
3-7
3-7. Brazing
Brazing is the joining of broken parts by means
of a nonferrous metal or alloy with a melting
point higher than 1,000° F., but lower than the
melting point of the parts to be joined. Many
broken tools, even those of high-speed steels, such
as taps and drills, may be repaired by this method.
The degree of damage usually determines the
alloy to be used. Silver alloy is used to braze
together pieces of a badly shattered tool of high-
carbon steel; other brazing alloys, less expensive
than silver, are used for simple fractures. A
1,300° F. alloy is used in all cases where great
binding strength is required and a slight local
loss of hardness does not matter. A 940° F. alloy
is used where full hardness must be maintained
at the cost of slightly less strength. For addi-
tional information on brazing refer to TM 9-237.
3-8. Welding
When practicable, welding is used to repair metal
tools and implements. This is especially true in
instances where fractured parts are irreplacea-
ble or so valuable as to make welding an econo-
mical repair procedure. Welding is fusing the
fractured surfaces together while they are in a
molten state. To produce the intense heat neces-
sary for fusion, the oxyacetylene torch is com-
monly used. Whether to weld or not depends a
Section II. REPAIR
3—10. Handles
Damaged tool and implement handles must be
either replaced or repaired.
a.	Metal Handles.
(1)	Smoothing. Metal handles with the sur-
face damaged in such a manner as to leave rough
burs or sharp slivers should be smoothed with
abrasives. Use emery paper if the damage is
slight. Use a file or a grinding wheel if the
damage is extensive and requires the removal
of a large amount of material.
(2)	Straightening. Straighten bent handles
in a vise or on an anvil.
(3)	Repairing fractures. Repair broken
handles by brazing (para 3-7) or by welding
(para 3-8).
b.	Wood Handles. Smooth roughened wood
handles with sandpaper. If handles are fractured,
they may sometimes be repaired by gluing; how-
ever, handles on all percussion tools (hammers,
axes, sledges, etc), which are designed to with-
stand considerable strain, must be replaced with
new handles or with serviceable used handles.
(1)	Kind of wood. When it is necessary to
make a handle from stock lumber, select tho-
great deal upon the carbon content of the steel
to be welded. In general, the lower the carbon
content, the more easily and satisfactorily the
fracture can be welded (table 3-2). For addi-
tional information on welding refer to TM 9-
237.
3—9. Oiling
Repaired tools and implements, if to be placed
in storage for any length of time, should be
washed with drycleaning solvent and coated with
a rust-preventive compound (para 3-13). If, how-
ever, the repaired tools and implements are to be
placed into immediate use, they should be lu-
bricated to facilitate operation and to prevent
rust. When lubrication is necessary, the follow-
ing instructions apply:
a.	On moving parts, friction surfaces, pivots,
slides, and worms, use engine oil (SAE 10) or
preservative lubricating oil (special).
b.	On nonoperating surfaces, use preservative
lubricating oil (special).
c.	On nonoperating surfaces where there is
extreme humidity, moisture, or salt air, use pre-
servative lubricating oil (medium).
d.	In oiltight gearcases, use engine oil (SAE
30).
e.	In grease-type enclosed gearcases, use gen-
eral purpose grease (No. 0).
OF COMPONENTS
roughly seasoned wood, straight-grained and free
from defects. If strength is desired, use hickory
(shagbark (shellbark), pignut, or mockernut).
When strength is not a major consideration, use
elm, ash, beech, maple, Sitka spruce, or southern
gum. Use only straight-grain wood, free from
warp, decay, loose knots, checks, shakes, splits,
slivers, bark pockets, larvae channels, and pitch
pockets.
(2)	Replacement procedure. The procedure
for replacing a handle varies with the type of
handle and the tool to which it is attached. The
following procedure governs replacement:
(a) Handles with ferrules.
1.	Pry the ferrule from the old handle
and tap it onto the new one.
2.	Pick-punch the old ferrule to the new
handle.
3.	Tap the new handle onto the tool,
(b) Handles for sockets.
1.	Pull the old handle out of the tool
socket. If the handle is broken off in the socket,
drill out the center and pry away the remaining
wood.
2.	Shape the end of the new handle to
make it fit snugly in the socket.
3-8
3.	Tap the handle to seat it’ in the
socket.
(c)	Handles pinned to shafts.
1.	File off the peened ends of the pin
which attach the handle to the shaft.
2.	Drive out the pin with a punch. Do
not use a cone-shaped punch because it will
spread the pin.
3.	Unscrew or drive the handle from
the shaft.
4.	Screw or force the new handle into
position, with the pinhole in the handle alined
with those in the shaft.
5.	Tap the pin into place and peen the
pin ends to hold the pin in place.
(d)	Handles on tangs.
1.	Select a handle to fit the tang. If
necessary, use a handle having a hole too small
SHAPING HANDLE
Figure 3-4. Replacing hammer handle.
for the tang; take a salvage tool with a tang of
the proper size, heat it, and insert it in the
handle to burn the handle opening to the proper
size.
2.	After wetting the tang, insert it in
the new handle.
3.	Tap the end of the handle on a flat
surface to properly seat it on the tool.
(e)	Screw-on handles. Several types of
screw-on handles are used as replacements. In-
stall these types of handles according to the
manufacturer’s directions.
(f)	Hammer handles (fig. 3-4, 3-5).
1.	Remove the old handle from the ham-
mer head. If the handle is tight, saw off the
Figure 3-5. Installing wedges.
3-9
DOTTED LINE SHOWS ORIGINAL SHAPE
Figure 3-6. Repairing a mushroomed wood head.
old handle close to the neck of the hammer head.
Drill a hole in the old handle and knock out the
remaining wood. Save the wedge.
2.	With a rasp or spokeshave, shape
the new handle to fit the hammer head.
3.	Assemble the head and the handle
for a tight fit by striking the end of the handle
with a mallet to seat it firmly in the head.
4.	Saw off any portion of the handle
projecting through the head.
5.	Remove the handle and saw a kerf
in the head end for the wedge. Note the place-
ment of wedges in similar-type hammers.
6.	Replace the handle and drive in the
wedge.
7.	Smooth off the wedge end of the
handle. If a wood wedge is used, finish the end
with a wood rasp; if a metal wedge is used,
finish the off the end of a grinding wheel.
NOTE
Sometimes a hammer handle needs only
tightening. To tighten the handle, re-
move the loose wedge and put in a
larger one. If the wedge remains tight
in the handle, but the handle is still
loose, drive a thin hardwood wedge or
an iron wedge into the handle beside the
original wedge.
(g)	Handles for mallets, mauls, sledges,
hatchets, axes, and adzes. Replace the handle of
each in the same manner as a hammer handle.
(h)	Mattock handles.
1.	Tap the butt of the handle on a solid
surface to loosen the head.
2.	Slide the head from the butt of the
handle.
3.	Insert the new handle, butt first,
through the head and slide the head into its
approximate position.
4-	Rap the head end of the handle on a
flat surface to tighten it to the handle.
(i)	Shovel handles.
1.	Cut, grind off, or drill out the peened
heads of the rivets attaching the shovel to the
handle.
2.	Drive out the rivets and pull the
handle from the shovel.
3.	Insert the new handle into position
on the shovel.
4.	Drill rivet holes through the new
handle.
5.	Insert the rivets and peen the rivet
ends to hold them in place.
(/) Saw handles.
1.	Remove the special screws and nuts
which attach the handle to the blade.
2.	Slide the handle off the blade.
3.	Position the new handle on the butt
end of the blade, with the screw holes in the
handle and blade alined.
4.	Install the special screws and nuts
which attach the handle to the blade.
3-10
3—11. Tool Handle Heads
Tool handle heads (such as those on chisels) that
have become battered or mushroomed from con-
stant hammering must be repaired.
a.	Wood Head. Use the following procedure
for repairing a mushroomed wood head (fig. 3-
6):
(1)	Remove the handle from the tool (1).
(2)	Saw off the mushroomed head, sawing
as close to the mushrooming as possible and still
leaving a clear end (2).
(3)	Turn the end of the handle down to
about 7/16 of an inch diameter for approximately
3/8 of an inch (3).
(4)	Cut leather or fiber washers to fit snugly
over the tip on the end of the handle, making
certain that the outside diameter of the washers
is slightly larger than the outside diameter of
the handle (3).
(5)	Place enough washers on the handle to
insure that their total thickness equals or slightly
exceeds the height of the tip on the end of the
handle (4).
(6)	Glue the washers onto the end of the
handle and clamp until dry (4).
(7)	Sand or grind the washers to conform
to the shape of the handle (5).
b.	Metal Head. Use the following procedure for
repairing a mushroomed metal head (fig. 3-7) :
(1)	Grind the head to original shape.
(2)	Temper the reground head (para 3-6c-
(3)).
MUSHROOMED METAL HEAD
GRINDING AWAY MUSHROOMED METAL
Figure 3-7. Repairing a mushroomed metal head.
Section III. REFINISHING
3—12. Preparation of Surface
Before attempting to refinish a tool or imple-
ment, be sure that it is free from dirt, grease,
and old finishing material. For the preparation
of the surface, observe the following procedure:
a.	Wood. Smooth wood parts by sandpapering
with fine-grained sandpaper.
b.	Metal. Wash metal parts in drycleaning sol-
vent and dry thoroughly.
3—13. Materials
The chief reason for applying finishing mater-
ials or preservatives to tools and implements is
to prevent them from rusting, corroding, and
deteriorating during periods of nonuse or ship-
ment.
a.	Paint, Enamel, Lacquer, Varnish, and Al-
lied Materials. Refer to paragraph 2-10.
b.	Compound, Rust Preventive, Heavy (5-lb
can). This is a viscous, greaselike, nondrying
petrolatum-type compound. When used on un-
painted metal surfaces it provides protection from
rust for long periods and withstands direct ex-
posure to the weather. It is not a lubricant and
all traces of it must be removed from coated
articles before they are placed in service. It can
be removed with drycleaning solvent.
c.	Compound, Rust Preventive, Light (5-lb
can). This is a greaselike, nondrying petroleum
compound less viscous than heavy rust-preven-
tive compounds. It provides protection for un-
painted metal surfaces for relatively long periods
when the preserved surfaces are not directly ex-
posed to the weather. It is not a lubricant and all
traces of it must be removed with drycleaning
solvent.
WARNING
The solvent used in the. following com-
pound is volatile and flammable and the
compound must be applied in the open
3-11
or in a well-ventilated room and away
from open flames.
d.	Compound, Rust Preventive, Thin-Film
(1-Gal Can). This is a liquid consisting of a
heavy, nonfluid, waxy compound thinned with a
volatile petroleum solvent. It protects against
rusting for long periods and can be applied over
painted or other surfaces without harmful ef-
fect. It is extremely adhesive and must be re-
moved with drycleaning solvent.
3—14. Methods of Application
For the best results, use the following methods
of application:
a.	Paint, Enamel, Lacquer, Varnish, and Al-
lied Materials. Refer to paragraphs 2-10 and
2-11.
b.	Compound, Rust Preventive. Apply rust
preventive compound (para 3-13b and c) hot in
order to obtain sufficient fluidity to adhere to
the metal surface. To accomplish this, place the
compound container in a vessel of water and
heat until the temperature of the compound is
between 180° F. and 200° F. Do not apply a flame
directly to the compound container; overheating
destroys the protective qualities and creates a
fire hazard. Apply the compound by use of one
of the following methods:
(1)	Dipping. The dipping process is the
most desirable because there is less danger of air
bubbles forming in the preservative film. The
compound film cools quickly after application to
the metal, thus tightening the film. The film
obtained by dipping is smoother and the thickness
is more uniform than that obtained by other
methods.
(a)	Heat the metal surfaces before dip-
ping; heat drives off some of the moisture film
adhering to the surface of the metal. The tem-
perature of the metal when dipped should be
lower than that of the compound in order to set
the film as rapidly as possible after dipping;
otherwise, a thin film will be obtained. If the
metal is not given a preliminary heating, the
pieces dipped should be allowed to remain in the
solution for a short time. This permits absorption
of the water film by the compound and heats
Section IV.
3-16. Essential Points of Inspection
When inspecting tools and implements for re-
pair, use the checklist in appendix В for guidance.
3-17. Methods of Inspection
Use the following procedure to inspect tools and
the surface of the metal sufficiently to obtain
good adhesion.
(b)	Dip pieces containing cavities in such
a manner as to allow the easiest escape of air
and complete coverage of surface.
(c)	After dipping, allow the pieces to
drain until cooled to room temperature. The
drippings are suitable for future use and should
be kept free of dirt.
(2)	Swabbing. When dipping is not prac-
tical, the swabbing process may be used.
(a)	Heat the compound to a slightly
higher temperature than for dipping, as it cools
before reaching the metal surface.
(b)	Make several applications of the com-
pound to work out the air bubbles and to produce
a uniform coating.
c.	Compound, Rust Preventive, Thin-Film.
Thin-film rust preventive compound is applied
cold. Dipping, brushing, or spraying is a satis-
factory method. Since the solvent used in the
compound is volatile and flammable, it should be
applied in the open or in a well-ventilated room
away from open flames. Do not add solvent be-
cause the compound already contains the correct
percentage of solvent. Do not use heat at any
time when applying thin-film rust preventive
compound.
3—15. Precautions
Preparation of the metal surface before the ap-
plication of a protective finish is most important,
because much corrosion is due to improper clean-
ing of the metal surface before the finish is
applied. Before applying protective finish, make
sure that the following precautions are taken:
a.	Metal surface is clean, dry, and free of all
traces of corrosion.
b.	Gloves are worn to prevent acid stains and
corrosion resulting from body perspiration.
c.	All condensation or sweating, caused by the
metals being brought into a heated room from
outdoors, is removed from metal surface.
d.	Finishing material is not applied
until the metal reaches room temperature
and is thoroughly dry.
INSPECTION
implements for repair:
a.	Inspecting Items for Damage. Handle in a
systematic manner each tool or implement to be
repaired. In most instances the order of the
inspection will be the tool or implement handle;
the joining or fastening of the handle to the tool
3-12
or implement body; and the body, blade, and
cutting edges.
b.	Repairing Items. After inspecting and not-
ing the amount of damage, repair the articles.
If no special instructions are given, repair the
damage in accordance with the methods dis-
cussed in paragraphs 3-1 through 3-15. Make the
repairs in the following order:
(1)	Straighten bent parts.
(2)	Repair broken parts.
(3)	Repair broken joints.
(4)	Secure loose joints.
(5)	Replace missing parts.
(6)	Repair surface damage.
(7)	Regrind and sharpen.
(8)	Retemper.
(9)	Prepare surface for refinishing.
(10)	Apply finishing material (preserva-
tive).
c.	Final Inspection. Upon completion of re-
pairs, give the item a final inspection to insure
that the following conditions are met:
(1)	All dirt, grease, and rust have been
removed.
(2)	The metal and wood used in replaced
parts are similar to that used in the original
construction.
(3)	Replacement handles are of standard
size.
(4)	Handles are made of sound material and
securely attached.
(5)	All cutting edges have been ground to
the correct bevel and sharpened, and wire edges
have been removed.
(6)	None of the parts are missing.
(7)	All components fit properly, stationary
parts fit with precision, and moving parts func-
tion without sticking or jamming.
(8)	All surface defects have been repaired,
worn serrations reworked, and j agged protrusions
filed smoottn-
(9)	Proper finishing or preservative mate-
rial has been applied and there are no skips in
the covering.
3-13
CHAPTER 4
REPAIR OF OTHER ITEMS
Section I. BASIC REPAIR
4-1. Cleaning
Dirt, grease, corrosion, rust, and in some in-
stances old finishing material, must be removed
from articles before repairs are attempted.
Figure 4-1. Procedure for cleaning aluminum and stainless steel.
Figure 4-2. Methods of holding aluminum items for
dipping.
a.	Wood. For instructions on cleaning of wood
articles, refer to paragraph 2-9b.
b.	Aluminum and Stainless Steel. To clean
aluminum and stainless steel articles, such as
canteens or other articles of the same material,
use four tanks (fig. 4-1) with special racks or
wire hooks, not constructed of brass or copper,
to hold articles (fig. 4-2). The uses of these
tanks in cleaning procedures are as follows:
(1)	Prerinse, running hot water. Dip arti-
cles in prerinse tank for 1 minute in water,
constantly overflowing at a temperature of 180°
to 212° F. Remove and drain articles.
(2)	Acid, 15 percent, liquid metal cleaner
solution. Combine 15 parts by volume of metal
cleaner solution with 85 parts of tap water. Dip
articles for 1 minute in rubber-lined tank con-
taining liquid metal cleaner acid bath solution.
Keep temperature of the bath at 190° to 200° F.
Remove and drain articles. Drain and recharge
the acid bath tank whenever, for example, 200
stainless steel or 100 aluminum canteens, or the
equivalent surface area of other articles per
gallon of solution have been cleaned; or, when
it is evident that the solution is so contaminated
with grease, dirt, or other foreign matter that
its effectiveness is impaired. Test acid bath solu-
tions once every 8 working hours to see whether
more metal cleaner is needed.
(3) Rinse, running hot water. Dip articles
in rinse tank for 1 minute in water constantly
overflowing, at a temperature of 100° to 200° F.
Remove and drain the articles.
(4) Final rinse, running hot water. Dip
articles in final rinse tank for 1 minute in water
at a temperature of 100° to 200° F., with water
constantly overflowing. Remove articles drain
thoroughly, and let stand to dry. Drain rinse
tanks after 15,000 canteens or articles of equiv-
alent surface area have been treated.
4-2. Straightening
Many articles are constructed in whole or in part
of sheet metal. Distorted sheeting on otherwise
serviceable articles must be straightened. Dents,
ridges, and channels are removed with special
straightening tools, both hand- and power-
operated.
a. Purpose of Sheet Metal Tools. Sheet metal
working tools consist of stakes, dolly blocks,
calking tools, rivet sets, and dolly bars. Punches,
shears, and hammers are also sheet metal work-
ing tools. Rivet sets and dolly bars are used to
form heads on rivets after joining sections of
sheet metal and steel work. Stakes are used to
support sheet metal while the metal is being
shaped. Calking tools are used to shape joints of
sheet metal. Dolly blocks are used in conjunction
with bumping body hammers to straighten
damaged sheet metal.
(1)	Types of stakes. Stakes (fig. 4-3) are
issued in a variety of types; each type is used
to fabricate sheet metal into a particular shape.
Most stakes can be clamped in a vise; the hollow
mandrel type is clamped onto a piece of work.
(2)	Types of dolly blocks. Dolly blocks (fig.
4-4) or hand anvils are available in several types;
heel, low crown, toe, general purpose, heavy duty,
and utility. Each type is used for supporting
damaged sheet metal during straightening opera-
tions.
(3)	Types of calking tools. Calking tools
(fig. 4-5) either have a long or short, straight,
square nose, or a bent or offset nose.
(4)	Types of rivet sets. Rivet sets used by
tinsmiths and blacksmiths to force pieces to-
gether are used similarly, but differ in shape and
capacity. Tinsmith’s rivet sets (fig. 4-5) are
lighter in weight and can only use small size
rivets, up to 5/32 inch. The blacksmith’s rivet
set handles 1/2-inch rivets.
(5)	Types of dolly bars. Ironworkers use
dolly bars (fig. 4-4) to form heads on 1/2- to
Figure 4-3. Types of stakes.
4-2
Figure 4-4- Dolly blocks.
Figure 4-5. Calking tool, rivet sets, and dolly bars.
As the hammer blow is struck, the dolly re-
bounds slightly from the panel, but returns im-
mediately because of the pressure exerted by
your hand. As the dolly block returns, accurately
place it for the next spot to be bumped.
(a)	Dinging on the dolly. Dinging on the
dolly means a glancing or slapping blow of the
bumping body hammer on top of sheet metal
with the dolly block held directly below tne
hammer blow as shown in figure 4-6. The result
of this process is that the metal is ironed smooth
between the working faces of the dolly and the
hammer. Each blow dings a spot about 3/8 inch
in diameter. Succeeding blows should be struck
1-inch rivets. These bars are either straight,
offset, or of the spring type. The straight and
offset types are 24 and 30 inches long; the spring
type is 6 inches long and with a 1-inch diameter
handle.
(6)	Use of stakes. Each stake is used to
form a different shape, as indicated by the il-
lustration (fig. 4-3). The work is positioned over
these anvils (stakes) and pounded with a heavy
hammer until the work is formed to the contour
of the stake.
(7)	Use of dolly blocks. A dolly block is
held against one side of a sheet metal panel with
one hand. The other hand strikes the opposite
side of the panel with a bumping body hammer.
Figure 4-6. Dinging on the dolly.
4-3
so that each new spot overlaps the previous spot.
Ding a row of spots across the edge of a damaged
panel. Next, ding another row adjacent to the
first row, and so on, until the damaged area is
covered with parallel rows of spots. This stretches
the metal only very slightly. The low-crown ham-
mer face striking against the dolly, which closely
fits the contour of the panel, minimizes the
stretching.
(b)	Dinging off the dolly. Figure 4-7 il-
lustrates dinging off the dolly process. The high-
crowned face of the bumping body hammer is
used and the blows are directed against the rim
of a dent. The dolly block is held against the
bottom of the dent and pressure is exerted to
force the dent out.
Figure J>-7. Dinging off the dolly.
(c)	Using the bumping body hammer.
The blow used in dinging is not a followthrough
blow such as used in driving a nail or in riveting.
The hammer must be held loosely and swung
with a wrist action, producing a slapping blow.
Figure 4-8 illustrates the path through which
the hammer travels. The average number of
blows per minute is 120 and in regular rhythm.
As each succeeding blow is struck, the hammer
rebounds as shown. It is then lifted by wrist
action to a point high enough to start the next
blow. Then, by a snap of the wrist, the hammer
descends for the next slapping blow. At no time
is the hammer gripped firmly. The fingers are
used to guide and control the hammer at the
beginning and at the end of the blow. During the
downward and upward path of the hammer head,
the end of the handle moves through a short
arc, and the hand by continued wrist action
follows along, loosely holding the handle and
ready to grasp the handle more firmly at the
end of the rebound. This operation requires skill,
but it can be acquired with practice.
(d)	Low-crown dolly. The low-crown dolly
is used in low-crown panels where medium- and
high-crown dollies would stretch the metal.
(e)	Toe dolly. The toe dolly, or shrinking
Figure i—S. Using a bumping body hammer.
dolly, is used on flat panels. Its thinness and
length make it accessible in narrow pockets. The
large flat face is convenient when shrinking metal
((8) below). The flat sides are used as an anvil
for repairing flanges on metal.
(f)	General purpose dolly. The general
purpose dolly is convenient to hold and has
several different working faces and two beading
and flanging lips. It is the most useful of the
dollies, since it has unlimited applications.
(g)	Utility dolly. The utility dolly has a
high crown with one narrow beading edge. The
thick rounded sides are used in short radii curves.
(h)	Heavy-duty dolly. The heavy-duty
dolly is used on extra-heavy gage sheet metal
which resists the action of lighter dollies.
(i)	Heel dolly. The heel dolly is used both
to reach into sharp corners and into areas having
large radii.
(8)	Shrinking sheet metal. When a panel
has been damaged so that it is permanently
stretched, it will, after it is restored to shape,
be too high in the stretched area. It cannot be
dinged down since there is no place for the
metal to go. It must be shrunk. Shrinking should
always be done following the metal bumping and
before the metal is finished. Basically, the
shinking operation is simply the heating of a
small spot in the center of the stretched area
and then upsetting the stretched metal into this
heated spot, making it thicker. Shrink a stretched
area in sheet metal as outlined in (a) through
(e) below.
(e)	Using a suitable torch with a small
tip, heat a spot 3/8 inch in diameter to a little
past cherry red in the center of the stretched
area (fig. 4-9). The heat expands the metal in
the entire stretched area, while the spot itself
DRIVE HEATED AREA DOWN
DINGING OFF
THE DOLLY
Figure k-S. Shrinking sheet metal.
rises into a low peak. Use care to avoid burning
a hole in the metal.
(b)	Remove the torch. After the spot
turns cheery red, strike the spot with a hard
blow of the bumping body hammer to drive the
spot down. This hammer blow upsets the hot
metal and is the mechanical action which shrinks
the metal. The spot will now form a crater instead
of a peak.
(c)	Very quickly, hold a dolly block up
against the bottom of the crater. At the same
time, tap down the rim of the crater with the
bumping body hammer (fig. 4-9). This is simply
a dinging off the dolly operation to smooth the
spot to proper level before metal finishing. The
expansion in the metal from the heat remains
in the metal during this operation. When dinging
the upset metal smooth, use a low-crown face
dolly block under low-crown metal, and a high-
crown face dolly block under high-crown metal.
(d)	Finally, quench or chill an area about
6 inches in diameter around the spot with a
water-soaked sponge. This chilling draws the
expansion out of the metal very quickly.
(e)	Continue shrinking additional spots
until the contour of the panel is in proper shape,
as determined by examining and by feeling with
the hand.
b. Care of Sheet Metal Tools. Keep all tools
free from rust and their working faces clean and
smooth. When not in use, wipe them with light
oil and store carefully. Do not use tools for a
purpose other than that for which they were
intended. For long periods of storage, coat all
metal parts with a rust preventive compound and
store in a dry place.
4—3. Soldering and Brazing
Both soft and hard soldering are used for repair
purposes. Soldering has some advantages over
welding and riveting, such as savings in equip-
ment and time; adaptability to inaccessible
places; use of low temperatures, affording protec-
tion to enamel, paint, and other finishes; and
protection against distortion caused by tremen-
dous heat of the welding torch.
a.	Soft Soldering. This process is used for
joining most common metals with a fusible alloy
that melts at a temperature below that of the
base metal. Soldering operations that require a
temperature of less than 750° F. are known as
soft soldering. The base metal is heated and
tinned on the surface by the solder filler metal.
A joint soldered by this method obtains its
strength from the penetration of the solder into
the pores of the base metal. Soft solders are
used where air- or water-tight joints, which are
not exposed to high temperatures, are required.
b.	Hard Soldering (Silver Soldering, Braz-
ing). This is a low temperature brazing process
with rods (filler metal) having melting points
ranging from 1,145° to 1,650° F. These tempera-
tures are higher than those used in soft soldering,
but considerably less than those of copper alloy
brazing.
c.	Joint Preparation. The parts to be soldered
should be free of all oxide, scale, oil, and dirt to
insure sound joints. Cleaning may be done by
pickling in caustic or acid solutions, filing, scrap-
ing, sandblasting, or other suitable means.
d.	Flux. All soldering operations require a flux
in order to obtain a complete bond and full
4-5
strength at the joints. Fluxes clean the joint area,
prevent oxidation, and increase the wetting
power of the solder by decreasing its surface
tension.
(1)	The following types of soft-soldering
fluxes are in common use: Rosin flux, the best
flux when soldering copper, electrical connections,
fine instruments, and small parts. Rosin flux is
noncorrosive and nonconductive. Zinc chloride
flux is used in heavier work and on untinned
copper, brass, bronze, Monel metal, nickel-plated
parts, galvanized iron, zinc, steel, and german
silver. A solution of zinc cut in hydrochloric
(muriatic) acid is commonly used by tinworkers
as a flux. Since zinc chloride and hydrochloric
acid are corrosive, all traces should be washed off
with a bicarbonate of soda solution.
(2)	When silver soldering, flux also usually
is required. The melting point of the flux, which
is composed of chlorides and fluorides, must be
lower than the melting point of the silver brazing
filler metal so that it will clean the base metal
and properly flux the molten metal.
e.	Forms of Solder. Solder is made in bar,
ribbon, and wire form. Wire solders may be
either solid or cored. Cored solder is hollow like a
tube and contains a core of flux. Ribbon and wire
solder are used with small irons and small, light
work. Bar solder is used with large irons or
torches on heavy work.
f.	Application. Solder joints may be made by
using gas flames, torches, electric soldering irons,
and nonelectric soldering guns. Electrical con-
nections and sheet metal are soldered with a
soldering iron or gun. Sweated joints may be
made by applying a mixture of solder powder or
paste flux to the joints, then heating the part
until the solder mixture liquifies and flows into
the joints. This is usually accomplished by the
use of a torch.
g.	Types of Soldering Irons. There are two
general types of soldering irons: electric heated
and nonelectric heated. The essential parts of
both types are the tip and the handle. The tip is
made of copper.
(1)	Electric soldering iron. The electric
soldering iron (fig. 4-10) transmits heat to the
copper tip after the heat is produced by electric
Figure 4-10. Soldering irons.
4-6
current which flows through a self-contained coil
of resistance wire called the heating element.
Electric soldering irons are rated according to
the number of watts they consume when operated
at the voltage stamped on the iron. There are
two types of tips on electric irons: plug tips
which slip into the heater head and are held in
place by a setscrew, and screw tips which are
threaded and screw into the heater head. Some
tips are offset and have a 90° angle for soldering
joints that are difficult to reach.
(2)	Nonelectric soldering iron. A nonelec-
tric soldering iron (fig. 4-10) is sized according
to its weight. The commonly used sizes are the
1/4-, 1/2-, 3/4-, 1-, 1 1/2-, 2-, and 2 1/2-pound
irons. The 3-, 4-, and 5-pound sizes are not used
in ordinary work. Nonelectric irons have perma-
nent tips and must be heated over an ordinary
flame or with a blowtorch.
h.	Additional Information. For additional in-
formaton on soldering or brazing refer to TM
9-237 and TM 9-243.
4-4. Riveting
In many instances, repairs require the removal
of the old rivets to disengage a damaged part
and the installation of new rivets to fasten the
replacement.
a.	Removing Old Rivets. Old rivets may be
removed in one of the following ways :
(1)	Grind off the head of the old rivet with
a power grinder and drive out the remaining part
with a pin punch or taper punch (fig. 4-11). Do
not use a cone-shaped punch; it might spread
the end of the rivet and damage the work.
(2)	Cut off the head of the rivet with a
cold chisel, and drive out the remaining part
with a punch (fig. 4-12). To facilitate removal
Figure 4-11- Removing rivet with grinder and punch.
KNOCK OUT RIVET USING A PUNCH
of the rivet head with a cold chisel, slot the
head with a hacksaw and chisel off half of the
head at a time.
Figure 4-12. Removing rivet head with cold chisel.
(3)	If the rivet is countersunk, drill out
the rivet head and punch the remainder of the
rivet from the hole with a taper punch (fig. 4-
13).
b.	Inserting New Rivets. The following rules
govern the insertion of new rivets :
(1)	Select a rivet similar to the one re-
Figure 4—13. Removing a countersunk rivet.
moved, making certain the body of the rivet fits
snugly in the hole and has sufficient length to
allow material for peening.
(2)	Insure a tight joint by cleaning thor-
oughly the faying surface (the surface between
the pieces), removing all burs and chips.
(3)	Aline the holes before inserting the
rivet. If the holes are unfair (do not exactly
meet), ream them out and use a larger rivet
(fig. 4-14).
(4)	Avoid all riveting faults (fig. 4-15).
CROSS-SECTION VIEW
PERFECTLY FAIR	NEARLY FAIR—	VERY UNFAIR—	TOO UNFAIR
CAN BE REAMED CAN STILL BE REAMED FOR REAMING
2 ) FRONT VIEW
Figure 4,-14. Method of alining rivet holes.
4-5. Welding
Welding is the only satisfactory method of re-
pairing certain items made of sheet metal (a
term which, in this manual, is restricted to metal
thicknesses up to and including 1/8 of an inch
(No. 11 gage)). When fractures occur on such
items, they usually occur at joints. For addi-
tional information on welding refer to TM 9-237.
4-8
too little material
FOR PROPER HEADING
©too much material and
HEADING NOT SYMMETRICAL
SMALL RIVET INSERTED IN UNFAIR HOLES
Figure 4—15. Improperly driven rivets.
Section II.	REPAIR OF COMPONENTS
4—6. Broken Parts
Replace all broken parts. If replacing is not prac-
ticable, repair them by soldering, brazing, weld-
ing, or riveting.
a.	Soldering. Refer to paragraph 4-3.
b.	Brazing. Refer to paragraphs 3-7 and 4-3.
c.	Welding. Welding repairs vary with the
form of material being worked upon. Refer to
paragraph 3-8.
(1)	Tubing. To repair a part made of tub-
ing, use one of the following methods:
(a)	Butt weld the broken edges together
(l,fig. 4-16).
(b)	Make a backup-ring joint by insert-
ing a ring and butt welding the broken edges
(2, fig. 4-16).
(c)	Make a fishtail joint by slipping a
larger tube with V-shaped ends over the fracture
and welding it in place (3, fig. 4-16).
(2)	Sheet metal.
(a) When repairing sheet metal, spread
the far edges of the fracture to allow for con-
traction of the metal. Generally, the distance
allowed between the far edges amounts to 2 1/2
percent of the total length of the weld or approxi-
mately 5/16 of an inch for every 12 1/2 inches.
4-9

I /////////////^^^^	w///////////#^^^
BUTT WELD
BACK-UP-RING WELD
Figure 4-16. Welding tubing.
BUCKLING DUE TO CONTRACTION
Where welding is intermittent, a greater allow-
ance must be made (fig. 4-17).
(b) If reinforcements are necessary, tack
weld a metal patch above and below the break.
(3) Heavy stock. Refer to paragraph 3-8.
d. Riveting. When practical, bridge the frac-
ture with butt straps and rivet them into place
(fig. 4-18).
USE OF SPREAD TO BALANCE CONTRACTION
4-7. Joints
For the repair of loose and broken joints, ob-
serve the following instructions:
a.	Refastening. To refasten a loosened joint,
clamp the parts together and run a bead of weld
along the length of the separation.
b.	Bracing. When it is evident that a bead
weld alone will not withstand the strain of nor-
mal use, tack weld either an angle, a U-brace,
or a strap reinforcement to the severely stressed
area. Place the reinforcement in an angle so that
it does not detract from the appearance of the
article and does not obstruct the operation of any
moving part.
Figure 4—17. Method of avoiding buckling when welding
sheet metal.
Figure 4-18. Repairing a fracture with butt
straps and rivets.
4-10
Section III.	REFINISHING
4—8. Preparation of Surface
Before attempting to refinish an article, be sure
that it is free from dirt, dust, grease, and oil
finishing material. For the preparation of the
surface, observe the following procedures:
a.	General. Refer to paragraphs 2-9 and 3-12.
b.	Metal Furniture. If the old paint is in bad
condition, remove it completely, using one of the
following methods:
(1)	Stripping. Use an alkali paint stripper,
6 to 10 ounces to a gallon of water, and apply it
hot in one of the following ways:
(a) Allow the stripper solution to drip
from an overhead perforated pipe onto the piece
being stripped until all the paint is off.
(5) Apply the hot stripper solution heav-
ily with an old brush. Do not use a spray gun
because the solution will go where it is not
wanted, and it may also ruin the spray gun. Let
the solution remain on the paint about 5 minutes,
then hose it off with cold water. Repeat the
process on spots where the paint has not come
off.
NOTE
If it is not convenient or desirable to
use alkali stripper, apply paint remover
or chlorinated solvents.
(2)	Sanding. Sand the old paint down to
the metal, using a portable electric sander to
reduce time and labor. After sanding, clean the
surface with a metal conditioner.
4-9. Materials
a.	Wood Components. Refer to paragraph 2-
10.
b.	Metal Components.
(1)	General. Refer to paragraph 3-13.
(2)	Brass. To get an oxidized finish (blue
black), throughly clean the brass and immerse
it in a solution of 1 pound of copper carbonate,
1 quart of ammonium hydroxide (commercial),
and 3 quarts of water. First mix the copper
carbonate and the ammonia, then add the water.
Allow the work to remain in the solution (kept
at a temperature of 175° F.) until the desired
color is obtained.
(3)	Iron and Steel. To get a galvanized
finish, thoroughly clean the article in hydro-
chloric acid, then dry it. Prepare a wrought iron
or mild steel pot of molten zinc. Sprinkle the
molten metal with sal ammoniac and carefully
dip the article into it. Drain off the surplus zinc
and plunge the article into water to wash away
any used sal ammoniac remaining on the surface.
c.	Metal Furniture.
(1)	Sheet steel. After cleaning the piece
of furniture with a metal conditioner, coat it
with a metal primer, such as zinc chromate. Ap-
ply three to five coats of enamel or lacquer,
lightly sandpapering the work between coats to
produce a deep luster.
(2)	Aluminum tubing and trimming. Give
aluminum tubing and trimming a satin finish by
rubbing with steel wool lubricated with a thick,
soapy solution; with a greaseless polishing com-
pound; or with No. 120 emery cloth to scratch
fine, light parallel lines into the surface sufficient
to eliminate all scratches or other blemishes
picked up during the repair. The lines should
run parallel with the edges of the tubing or of
the trimming. If welds have been made, they
should be blended in by being rubbed and given
a mist coat of aluminum lacquer (fine aluminum
paste in lacquer) or a shade that will blend in
smoothly and harmonize with adjacent surfaces.
4-10. Methods of Application
a.	Brush. Refer to TM 5-618 and TM 9-213.
b.	Spray Gun. Refer to TM 5-618 and TM
9-213.
c.	Dipping. Refer to paragraphs 3-145(1) and
4-15.
d.	Swabbing. Refer to paragraph 3-145(2).
4-11. Inspection
a. Initial Inspection. When making the initial
inspection, use the checklist in appendix В for
guidance as to the essential points of inspection.
5.	Repair the Item. After inspecting and not-
ing the amount of damage, repair the articles.
If no special instructions are given, repair the
damage in accordance with the methods dis-
cussed in paragraphs 2-1 through 2-11, 3-1
through 3-15, and 4-1 through 4-11. Make the
repairs in the following order:
(1)	Straighten bent parts.
(2)	Repair broken parts.
(3)	Repair broken joints.
(4)	Replace missing parts.
(5)	Tighten loose joints.
(6)	Repair surface damage.
(7)	Prepare surface for refinishing.
(8)	Apply finishing material.
4-11
c. Final Inspection. Upon completion of re-
pairs, give the articles a final inspection to in-
sure that the following conditions have been
met:
(1)	The materials used for repair and re-
placement are similar to those used in the orig-
inal construction.
(2)	All welded, brazed, and soldered repairs
have been thoroughly cleaned and smoothed.
(3)	All metal furniture joints have been se-
cured and braced sufficiently to withstand hard
use.
(4)	No parts are missing.
(5)	Components fit properly, stationary
parts fit with precision, and moving parts func-
tion without sticking or jamming.
(6)	All surfaces have been properly pre-
pared for refinishing.
(7)	The proper finishing material has been
applied and there are no sandy spots, orange-
peel effects, or skips in the covering.
(8)	All special instructions for the inspec-
tion and repair of the articles have been followed.
4-12
	APPENDIX A REFERENCES
1. Army Regulations AR 310-1 AR 310-25 AR 310-50	Military Publications—General Policies. Dictionary of United States Army Terms. Authorized Abbreviations and Brevity Codes.
2. Department of the Army Pamphlets
DA Pam 1'08-1 DA Pam 310-series	Index of Motion Pictures, and related Audio-Visual Aids. Military Publications Indexes (as applicable).
3. Field Manuals FM 21-5 FM 21-6 FM 21-30	Military Training Management. Techniques of Military Instruction. Military Symbols.
4. Technical Manuals ГМ 5-460 TM 5-461 TM 5-611 TM 5-618 TM 5-704 TM 9-208-1 TM 9-213 TM 9-237 TM 9-243 TM 9-247	Carpentry and Building Construction. Engineer Handtools. Repairs and Utilities: Post Engineer Shops. Paints and Protective Coating. Construction Print Reading in the Field. Cleaning of Ordnance Materiel. Painting Instructions for Field Use. Operating Manual: Welding Theory and Application. Use and Care of Handtools and Measuring Tools. Materials Used for Cleaning, Preserving, Abrading, and Cementing Ord- nance Materiel; and Related Materials Including Chemicals.
TM 10-450 TM 10-455	Sheet Metal Work; Body, Fender, and Radiator Repairs. Body Finisher, Woodworker, Upholsterer, Painter, and Glassworker.
5. Technical Bulletins ТВ QM 40	Quartermaster Maintenance Instructions; Refinishing of General Office Furniture.
6. Federal Specifications FED-SPEC-511-L-P	Plastic Sheet, Laminated, Thermosetting, Cotton Fabric Base, Phenolic- Resin, Post Forming.
FED-SPEC-513C-L-P	Plastic Sheet, Laminated, Thermo-Setting, Paper-Base Phenolic-Resin.
7. Military Specification MIL-P-15035-C	Plastic Sheet, Laminated, Thermo-Setting Cotton-Fabric-Base, Phenolic- Resin.
8. Military Standard MIL-STD 20 MIL-STD-171-B	Welding Terms and Definitions. Finishing of Metal and Wood Surfaces.
9. Military Standardization Handbook
MIL-HDBK-691-A	Adhesives.
A-1
APPENDIX В
INSPECTION CHECKLIST
Material		Surface		Construction	Cutting edge (tools)	Parts (including hardware)		
Wood	Metal	Wood	Metal					
Checks	Flaws	Blisters	Burs	Badly fitted joints	Beveled angle	Bails	Cabinets	Cutters
Decay	Irregularities	Burns	Chips	Badly fitted parts	incorrect.	Bases	Cans	Eyes
Excessive cross grain	Wrong metal	Chips	Corrosion	Bents parts	Bevel not uniform	Bearings	Caps	Fasteners
Improper species		Damaged finish	Cracks	Broken joints	Beveled on wrong	Blades	Chains	Ferrules
Knots		Dents	Damaged finish	Broken parts	side of the blade.	Bodies	Chests	Frames
Mixed species		Dirt	Dents	Faulty riveting	Dulled	Bolts	Chucks	Frogs
Shakes		Flaked finish	Dirt and grease	Incorrect dimensions	Faulty fit of edges	Bottoms	Clamps	Funnels
Splits		Gouges	Holes	Loose joints	Incorrect shape	Boxes	Connectors	Gears
Worm holes		Loosened grain Not sanded Peeled finish Poor finish Saw cuts Scratches Skips Spots and stains Torn grain Wrong finish	Improper finish Loose filings Open welds Poor finish Rough welds Rust Scratches Slivers Worn serrations W rong finish	Missing parts Poor soldering Warped parts Weak welds Wrong parts	Nicked Scratched Temper burned out Wire edge not removed.	Braces Burners Grates Grips Handles Hasps Heads Hinges Holders Hooks Inserts Irons Jaws Knobs Levers Teeth Thimbles Tines	Covers Cranks Lines Locks Lugs Nozzles Nuts Pans Pins Pipes Plates Racks Rails Ratchets Reflectors Tubes Valves Washers	Generators Globes Rings Rivets Rods Screens Screws Shanks Sleeves Slides Sockets Springs Staples Straps Tangs Wedges Wheels Wrenches
GLOSSARY
Adherend Adhesion AUoy	—An object bonded or to be bonded to another object by an adhesive. —Sticking or being stuck together. —A substance composed of two or more metals intimately united, with characteristics different from those of its ingredients.
Austenite Bond Braze	—An exceedingly tough steel, but not as hard as other steels. —To attach materials together by adhesives. —To join two pieces of metal by fusing a layer of brass or brass alloy between the adjoining surfaces.
Cohesion	—The state in which the particles of a single substance are held together by chemi- cal forces.
Concave Convex Corrosion	—Curved inward. —Curved outward. —The slow wearing away of metals by chemical attack, of which rust is a common form.
Ferrule Fire on Flux	—A metal ring or band put around the end of a tool handle. —To bake on with intense heat. —A substance used to remove oxide from metal surfaces to be soldered or weld- ed, and thus promote their union.
Laminate	—A product made by bonding together two or more layers of material with adhesive. To unite layers of material with adhesive.
Martensite Mortise Oxide Pickle Ply Rosin	—The hardest and most brittle type of steel. —A cavity cut into a piece of wood or other material to receive a tenon. —To combine with oxygen; rust and burning are common forms of oxidation. —A bath of acid to cleanse a metal surface in preparation for painting or soldering. —Thickness or layer. —A rosin obtained from pine trees, either as a residue in the distillation of the sap (gum rosin) or as an extract of the stumps and other parts of the tree (wood rosin).
Scribe Sorbite Square on Tang Tenon	—To scratch with a pointed instrument, such as a scriber or pair of dividers. —This is a steel with less hardness than troostite, but with added toughness. —The position of a spray gun when it is at right angles to the area to be sprayed. —A projecting prong or tongue on a tool to which the handle is connected. —A projecting portion of a member left by cutting away the material around it for insertion into a mortise to make a joint.
Tepid Thermosetting	—Moderately warm. —Capable of being converted to a relatively infusible state (by the action of heat, catalysts, ultraviolet light, and similar means).
Tine Troostite Turn Veneer Viscosity	—A tooth on a fork or rake. —A steel almost as hard as martensite, but noticeably less brittle. —To turn or round off, as on a lathe. —Thin sheets of material such as wood. —The measure of a liquid’s internal resistance to flow or its degree of thickness.
Glossary—1
By Order of the Secretary of the Army:
Official:
VERNE L. BOWERS
Major General, United States Army,
The Adjutant General.
Distribution:
Active Army:
CONARC (4)
Div (2)
Regt/Gp/bat gp (2)
Instl (2)
Br Svc Sch (2) except
USAOC&S (200)
Army Dep (5)
Cen (5)
Arsenals (5)
PG (4)
Units org under fol TOE :—2 ea.
10-417
10-437
10-500
29-15
29-16
29-21
29-25
29-26
29-35
29-36
ARNG: State AG (3); units—same as active Army
US AR: Same as active Army.
For explanation of abbreviations used, see AR 310-50.
W. C. WESTMORELAND,
General, United States Army,
Chief of Staff.
29-55
29-57
29-75
29-79
29-99
29-105
29-107
29-109
29-118
29-134
29-135
29-138
29-139
29-147
29-207
29-208
29-245
29-247
29-610
29-620
except allowance is one copy each.
☆ U.S. GOVERNMENT PRINTING OFFICE: 1971—421-714/20049A